What Am I Doing?

This beets me, why we all do thinks that we know, deep down are of no use. I once read an article about why humans mas***bate. One possible answer is because we seek pleasure. But If that so, if we humans really seek pleasure and have knack for it, then why do we put up thinks till the day before exam, and then the chances of the examination going bad increases. Isn't it more pleasurable to be sure of getting good grades by doing thinks when there is still time. Scratching feels pleasurable, then why do we not get ourselves bit by mosquitoes purposefully to induce scratching sensation?

So you see what we do is not always because it leads to pleasure, all these time when I was thinking that getting out of college will be very pleasurable, well it is not. You feel the feeling of accomplishment then that too dies soon. Am I wasting my time doing crappy things, thinking that someday I will get pleasure. Well I also must mention pleasure can be different for different people, for me no pleasure is grater than having confidence. 

We waste our health for earning money and behave like we will live forever. Then some day his body will start to ache and he will loose all his money to get back health, he starts to think that he have 100 more years to live, then then suddenly dies, thinking he has not lived his life at all..having not being to that place he always wanted :(