I think most people age gradually, taking on more and more responsibilities, become more and more adult as time goes on. I think excess marijuana can really slow that down. I know a few people who are in their 50's, but smoke so much, that I don't think they've matured since 15 or 16. Some people are thrust into adult situations, and either sink or swim. I got pregnant (accidentally) at 19, and the second I found out I was pregnant, i stopped drinking and doing other bad things, and I found a job and an apt. (instead of living with my parents, which I was doing between semesters), and took responsibility for the pregnancy, and for figuring it out with my BF. My son is now 7 1/2, and has been joined by 2 sisters, (same father), and we're married, and pretty happy, and pay our bills, and my kids eat vegetables almost every meal, and I just try to do my best! I just turned 28, and I think I'm as grown up as I'm going to get, barring any tragedies. Tragedy ages you quick.