If we can get rid of the parasitic material desires that suck our mental energy, we will be amazed at how much our mental energy we have at our disposal.
Many of us may sometimes feel fed up with the way things are going in our lives. At such times, we feel mentally tired even when we are not physically so. This mental exhaustion makes many people seek relief in illusion through time-wasting entertainment at best and self-defeating addiction at worst. What causes this mental tiredness? It can have several causes, but a common, major, and avoidable cause is the indiscriminate over-exertion of our capacity to desire. This over-exertion results from unwittingly welcoming too many superfluous desires into our minds. The Bhagavad-gita (16.21–22) indicates that these distracting desires which prevent us from acting in our best interest come from three main sources: lust, anger, and greed.
Lust and greed often fuel our desires for the many worldly objects that enter our vision and imagination, be they glitzy forms or jazzy products. These desires are innumerable and endless, and most of them are practically unfulfillable. Consequently, a conscious or subconscious irritation builds up within us. When this irritation becomes intolerable, it makes us sitting ducks for anger, which perverts us into becoming sulky (mentally angry) or snappy (verbally angry) or even beastly (physically angry). In this way lust, greed, and anger cumulatively divert our mental focus away from the main goals of life, both material and spiritual. The resulting inattentiveness makes us falter and blunder while pursuing those goals. As our plans misfire and backfire, we start getting mentally exhausted and exasperated at how nothing seems to be working in our lives.
Thus, our mental exhaustion originates not so much in the external difficulties that life brings our way as in the internal diversions that prevent us from treading that way effectively. These diversions of lust, greed, and anger are thus like mental parasites that live on and live off our mind’s energies. That’s why the Gita wisely urges us to proactively immunize ourselves from these debilitating parasites, and thereby keep ourselves mentally energized and focused on our worthwhile aspirations.
At this point, some of us may object: “Not so fast! Even if I can’t fulfill all the desires that come to my mind, I can fulfill at least some of them. After all, fulfilling material desires is the way to happiness. Why should material desires themselves be compared to parasites?”
Making Our Intelligence FIT 
Material desires are comparable with parasites because they almost always subvert, even sabotage, our best interests. When they divert us from our life’s goals, they are the sources of distraction, as explained above. But when they themselves become our life’s goals, they have an even more deleterious effect: they become the sources of frustration and sometimes even devastation. This is the surprising and challenging assertion of the Bhagavad-gita (5.22), which states that intelligent persons stay away from material pleasures the goals of material desires because they recognize that such pleasures lead not to happiness but to misery.
We can make our intelligence fit to realize the truth of this Gita verse by using as a contemplation tool the acronym FIT (Futility, Insubstantiality, Temporality) that encompasses the three possible results of seeking material pleasures:
1.Futility: We desire to enjoy, but the opportunity never turns up; e.g., we long for our favorite delicacy, but the menu doesn’t include it.
2.Insubstantiality: We get the opportunity to enjoy, but the enjoyment turns out to be anti-climactic; e.g., the menu includes our cherished delicacy, but it is poorly cooked and falls far below our expectations.
3.Temporality: We enjoy the pleasure, but it ends too soon either due to limited availability externally or limited capacity internally, leaving us tormented by the craving for more; e.g., the delicacy tastes good, but our enjoyment ends earlier than we would like either because the servings of the delicacy are limited or because the capacity of our stomach is limited.
Thus in all possible eventualities, the quest for material pleasure sooner or later leads to frustration. This vindicates the parasite-material desires analogy: just as parasites harm the bodies that host them, material desires harm the minds that host them. 
Of course, one’s inability to enjoy a favorite delicacy may not be a serious matter, but the inability to perceive the danger inherent in pursuing material pleasures can have far more serious ramifications. Some material desires acquire a lifelong vicious grip on 
people’s minds and impel them to perpetrate vicious acts again and again. After all, aren’t barbaric rapists and other sex abusers driven mostly by unbridled lust? Aren’t ruthless racketeers who swindle millions of people of millions of dollars goaded largely by unmanageable greed? Aren’t cold-blooded vendetta seekers actuated principally by uncontrollable anger? If we understand the inherent danger in pursuing material pleasures, then we see the tragedy behind their insanity; they inflict so much suffering on people who hope for happiness, but their attempts to find happiness are hopeless. If only they could make their intelligence fit, they would see that their parasitic material desires are not just wasting their mental energy, but are ruining their entire lives, and the lives of so many others. All for nothing for a pleasure that is at best measly and meager.  
Most of us may not be so grievously controlled and depraved by our parasitic material desires. Nonetheless, even when these desires exercise over us a level of subjugation that doesn’t impel us to violate legal or moral boundaries, still they take a colossal toll on our mental energies. For example, lust masquerading as love may induce within us the desire for a particular life-partner, thereby compelling us to dream and scheme for days and months and years. Let’s apply our fit intelligence to see how FIT may play out here:
1. Futility: That person rejects us outright, thereby bursting the bubble of our fantasies with one unbearable prick.
2. Insubstantiality: That person accepts our proposal and formalizes the relationship, but then we discover that he or she does not live up to our dreams and that there are some fundamental incompatibilities between us. We are left to watch in helpless dismay as the bubble of our dreams deflates gradually and then disappears.
3. Temporality: That person satisfies our heart’s desires to some extent, thereby inflating the bubble of our expectations, but then destiny mercilessly ruptures our relationship; an unfortunate misunderstanding or an untimely demise bursts the giant bubble of our hopes in a heart-wrenching reversal.
In sad cases like these, our lust-induced misdirection, irrespective of whichever dead end it meets, costs us dearly on the mental plane.
Similarly, all our material desires be they for a house, a car, a prominent position, or whatever else extract a significant mental cost with a return that is near zero. Material desires can be of many kinds and for many things, but the Vedas say that they come from six sources: lust, anger, greed, envy, pride, and illusion. Among these, the Bhagavad-gita (16.21) highlights the first three as especially capable of misdirecting the soul, so we are focusing on them.
When sober sustained analyses of the nature of material pleasure makes our intelligence fit, then we recognize that such enjoyment is unfit to be desired by us; they will simply suck and sap our mental energies, as parasites would suck and sap our physical energies. 
This recognition needs to bring about a radical shift in our perception of the sources of these desires: worldly temptations. Just as intelligent people treat parasites with caution and suspicion, always alert to keep them out of their bodies, we need to treat our parasitic material desires with caution and suspicion and be alert to prevent them from entering our minds by way of temptation.
Response to Temptation: Welcome Tune or Alarm Bell?   
The Bhagavad-gita (3.41) warns us to recognize temptation sexual temptation in specific and material temptation in general as a “great symbol of sin” (papmanam) and fight it off as soon as it makes its seductive and deceptive appearance.
But when we are intellectually inert, the arrival of temptation sets off a welcome tune in our consciousness; our lethargic intelligence has no strength or determination to unmask the treacherous facade of temptation. Consequently, we get helplessly, even eagerly, carried away by the doomed hope that indulging in the temptation will make us happy. In other words, we welcome the parasites, mistaking them to be benevolent.
In contrast, when we are intellectually alert, the arrival of the same temptation triggers a warning bell in our consciousness. Our robust intelligence swings into action to punch out the temptation, knowing well that temptation is a forerunner of emotional distraction that can snowball into spiritual destruction. Consequently, we gird ourselves for an inner battle that leads to a gradual but inevitable triumph, if we seek shelter and strength in the remembrance of Krishna.
Just as freeing the body from parasites requires a systematic and appropriate treatment plan, fighting the mind from parasitic material desires requires a systematic and appropriate spiritual treatment plan. In fact, the Bhagavad-gita (6.36) states that without such a plan, the attainment of self-mastery is nearly impossible, whereas with such a plan, it is entirely possible. Let’s now look at what such a plan involves.
The Way to Say No Is to Say Yes
Many of us, even after recognizing the need to curb material desires, often remain preoccupied with the temptations that we plan to evade and avoid. This negative or defensive attitude in dealing with the parasitic desires makes the fight more difficult than it needs to be.
In order to stay away from temptation, many of us use two faculties:
1. Moral conscience, which tells us it is the right thing to do, and…
2. Philosophical conviction, which tells us it is the beneficial thing to do. 
This moral and philosophical discernment is necessary; without it, self-restraint often becomes an exercise in meaningless and purposeless self-torture. However, discernment is necessary, but not sufficient. With discernment, we recognize self-restraint to be right and beneficial, but don’t experience it to be joyful. That’s why the Bhagavad-gita (2.60) states that even a person of discernment endeavoring for self-restraint is overpowered by temptations.
The next verse (2.61) urges us to complement discernment with engagement. When we engage ourselves in service to Krishna especially when we engage our minds in the service of remembering Him then spiritual happiness doesn’t remain an abstract conception or a utopian aspiration; it becomes a concrete reality and a living experience. The Bhagavad-gita (2.62–63) describes how giving our attention to an object stimulates our desires and initiates our attempts to attain that object. This universal psychological principle neatly summarized in the phrase “whatever catches our attention catches us” normally binds us when we contemplate the material objects depicted in billboards and commercials. But this same principle can also free us if we intelligently re-direct our attention towards Krishna. Krishna makes Himself available and attractive to us by appearing in various ways: His enchanting Deities, His soothing holy names, His electrifying kirtans, His magnetizing pastimes, His loving devotees, or His fulfilling service. These are, in a sense, Krishna’s commercials and billboards. If we strive to consciously give our attention to the aspect of Krishna that most attracts our heart, we will soon pleasantly discover that Krishna has caught our attention and has thereby caught us. And Krishna’s catching us is supremely auspicious. When He fills our heart with His remembrance and love, material desires are crowded out, and we are freed forever from their torturous infection.
Moreover, service to Krishna is not restricted to activities that are externally, directly connected to Him. Even our worldly responsibilities can become service to Krishna if we keep Him in our hearts and strive to perform those responsibilities as devotional offerings to Him. Thus, giving up material desires doesn’t necessitate giving up all activities or responsibilities. What is parasitic and needs to be given up is the false hope that material things can make us happy; only our loving relationship with Krishna can make us truly happy.
But once we have made reviving that relationship with Krishna the central driving purpose of our life, then we can orient our worldly activities with that purpose. When we start using our devotional creativity to discover in every situation, every event, every activity, every interaction, the hidden opportunity to serve Krishna and then say yes to that opportunity, the resulting devotional connection with Krishna through internal remembrance and external service gives us profound spiritual fulfillment. Once we start tasting and valuing this fulfillment, then temptations are exposed for what they are: sources of distraction, not gratification. At that stage, saying no to such temptations becomes not just right and beneficial, but also joyful.
Moreover, Krishna consciousness has such an extraordinary transformational potency that it can convert a parasitic relationship into a symbiotic one. The great Vaishnava saint Narottama Dasa Thakura indicates in his Prema-bhakti-chandrika that, once we redirect our heart to Krishna, even lust, greed, and anger can be repurposed as aids in our spiritual progress. We can channel lust in desiring the best things of the world for Krishna’s pleasure. We can utilize greed to tirelessly relish Krishna’s unlimited glories. We can redirect anger to eliminate the misconceptions and miscreants that are obstructing Krishna’s message of love from reaching all of His children.
Thus, saying a wholehearted yes to Krishna is the most effective way of saying a decisive no to parasitic material desires.
We discussed how material desires are like parasites in four ways:
1. Just as a mild parasitic infection de-energizes us physically, a mild infection by material desires de-energizes us mentally.
2. Just as a severe parasitic infection causes us acute bodily suffering, a severe infection by material desires causes us the acute mental suffering of frustration.
3. Just as we see parasites as potential threats for the body, we need to see material desires as parasites for our minds.
4. Just as we would take an authentic and systematic medical treatment to cure ourselves of parasites, we need to take the authentic and systematic spiritual treatment of Krishna consciousness to cure ourselves of material desires.
When we realize material desires to be parasitic and strive to free ourselves from them, then we will save our mental energy from being dissipated by stray material cravings. We will surprise ourselves with our remarkably high mental energy levels and will be able to achieve much more, both materially and spiritually. Materially, we will be able to fulfill our worldly responsibilities with greater competence and diligence. Spiritually, more importantly, we will be able to cultivate and experience spiritual happiness in this very life. And at the end of this life we will be able to return to Krishna for a life of eternal love and happiness.
Caitanya Carana Dasa is the associate-editor of Back to Godhead (US and Indian editions). To subscribe for his daily Bhagavad-gita reflections, please subscribe for Gitadaily on his site thespiritualscientist.com.