The trick to it is putting yourself in that mindset. See, ever since originally moving out after highschool, I have never lived in a situation which nurtured responsibility. I've lived in like 5 party houses, and everyone probably better then the last. The house I just lived in for two years contained 3 'young proffesionals', 2 full time students, and one rotating roomate. It was a lot like living in a party house in university, but everyone had more money so it was even more ridiculous.
Coming out of that I was faced with the prospect of living in an apartment with one or two other people. I can't think of anything that would bore the shit out of me more. So I figure I'll save some cash and then get my own apartment where I can do sketchy shit and not tell anyone about it (read: dirty girls).
But as someone once described it to me: "After you turn twenty, you're in a new tier of responsibility. You remain in that tier until at least thirty. If you move up before thirty, you're playing the game wrong and you're really only cheating yourself."