Another movie like this is Dr Jekyll and Mr Hyde. People act depending on the situation, it's a self preservation instinct.

Conservative and secure vs. rebellious, adventurous and dangerous Film: "Fight Club". The main character is dull, conformist and secure - his other side is rebellious, volitile and violent. Don't worry though - my rebellious side is always non-violent. I used to let it out more when I was younger. I managed to fuse my conformist side with the rebellious one through the years. Other contending parts of me still haven't been integrated, though. I always liked the rebellious side more before things got resolved.

they say every beautifull place have a ugle side, same as to man i can't say that i am good one as i always keep my dark side which the evil one if you can see my body has lot of scar's from my past.it's my temper from my youth that cause it.as now i try to hide that one and expose my bright side to every one.i can be a good friend as good as you have now but dont push my self in to the limit i can be the worse enemy that you will ever imagine."trust the man but dont trust the devil inside of them" cowboy...