Why do I do that?

I have a tendency, a habit really, to do things that I know aren't going to make me happy in the long run. I'll cancel plans with a friend because of one reason or another and then regret not having plans later. I'll Decide to sleep instead of going to the grocery store or instead of finishing up a homework assignment and then I will have to wake up far too early and scurry to finish my homework or just go hungry one night because of a lack of food that sounds good. So when I do these things that I know I will regret later I don't understand what is going through my head. I honestly cannot remember what I was thinking when I do these things or decide not to do these things. The prevailing memory is the one that I feel *later* when I regret what I have done.

You'd figure that it would be like touching a hot stove and getting burned: you take special care not to let it happen again. But nooooooooo. Even though I know I'm going to get burned I still use large flailing gestures and don't protect myself at all while I'm cooking around the stove.

And yet? I continue none-the-less. Someone explain that one to me because I sure don't get it. Maybe I should go get a shrink...