The Mishnah in Avos states: "Sleeping late in the morning, getting drunk in the afternoon, and engaging in childish conversation remove a person from this world."
Now, this Mishnah seems difficult to understand. We can see how the pursuit of the passions discussed in a different Mishnah in Avos: kinah, ta'avah, and kavod - envy, physical desire, and the quest for honor - "remove a person from this world," for these are all serious character flaws. But the Mishnah we mentioned first makes no mention of any true aveirah, just bad habits!
Are bad habits sufficient to "remove one from the world"?!
The answer is that when one indulges in fleeting pleasures such as those cited by the Mishnah, he loses focus on achieving the real ones.
Certainly, sleeping late, drinking too much, and speaking silliness are problematic behaviors, but there is a more pernicious problem here: When one satisfies himself with counterfeit pleasures he forfeits his pursuit of the real ones ... and eventually he loses both.
Before performing an aveirah, ask yourself, "What am I doing? What am I gaining? A moment's pleasure, a fleeting jolt. But how will I feel after I'm done with achieving that pleasure? That moment will leave in its wake an avalanche of self-revulsion, regret, shame, and remorse."
And that's considering only the immediate, post-aveirah emotion. Taking the longer view, the futility of this moment's rush is even more obvious. In exchange for this distraction, one destroys his very essence, his kedushas Yisrael, and abandons the eternal pleasure of Olam Haba.
Go for the gold, the real, enduring pleasure of being connected to Hashem.
In fact, the Gra writes that a person need not wait for Olam Haba to be compensated for his sacrifice. In the Gra's words: "Any improper pleasure that a self-indulgent person enjoys after much effort comes to a decent person in a rightful manner without any work."
This is amplified by the Steipler Gaon, who writes similarly:
Realize that when one overcomes [his yetzer hara] and withstands the test, Hashem's Name is sanctified greatly, and the person's merit is awesome and wondrous. Even in this world the person will, in the long run, see gratification. For any pleasure from which a person refrains so as to honor Heaven will be repaid to him in another way, in a permissible manner, over the course of time.
By withstanding the immediate rush of seeing something, one receives a parallel, but permitted, pleasure at some later point in his life.