[dsfyu404ed]

Meh. Self discipline is very much a learned skill. I've seen plenty of high school age who have as much self discipline as your average middle age adult and vise versa. I think whether or not you have good personal responsibility at 18 depends a lot on whether you're given chances to build that skill from age 10-18 or so. People tend to mostly try to meet the expectations of society and society doesn't expect much from 18yos.