I don't know why people do it. Probably because of the thrill it brings. When you think that you're not supposed to do it, you get excited and with the fact that you're not allowed to make it happen.
Me? I'm guilty as charged. I like the thrill - I probably even live for the thrill. My whole being is all about excitement. Everything will be a bore without and that's why I look for it. That's right, I'm a thrill seeker, if you must. But then again, who isn't?