Self hurting!

I was in a bad mood last night and thought that I am hurting myself by not studying. Then as a flash it struck me, is it possible to hurt yourself ??? ...knowingly? I wondered for sometime ...maybe it is. Don't I hurt myself sometimes just to show that I can endure the pain ? Like cycling down 12-13 kms to town and not stopping once. I do not study when I really need to. Then I decided to ask about it from you-know-who, yes the giant himself The Google God! ...And here is what I found. This site is very scary, giving an insight on the darkest of the human pyschology. Is it all really true? how can someone "cut" himself/herself? won't it hurt ? Hurt...some people really don't feel it because

"Some people still don't feel pain because the production of endorphins is too high. Endorphins act as natural opiates, pain killers, and anesthetics. When too many of them are being produced, a person does not feel pain.

Having said all this ... yes, there are people who self-injure who feel pain. Of course there are. To some people, this pain is welcome. They feel like they are bad in some way and that they deserve to hurt. Or they may like the pain because the sharper physical pain blunts out the emotional pain."

Hmm so the hurt funda is now clearer. But but but why would I do it in the first place ???
Reason in my view is the fucking mind! it plays games ..Why do people drink ? dope? just to relieve the pain(?) ...this may be a similar effort towards the same. Creating a pain greater than the emotional pain to dwarf it in front of the physical one.
Wow ! this is something I am gonna search more about. Don't worry I am not going to be a "cutter"... I ve better things to do :)