If you do it because you want a particular scar, it's about the scar and not the injury. If you do it as a coping mechanism without really wanting to, that can be more a lack of willpower.
Quick question for you, why do you ask a question like that? Do you need help of some sort, an online friend to vent to, something else or nothing like that?
Also, it makes you closer to death and that's about all it does