When I was little, I had a group of friends that thought it was really stupid that I started doing drugs. When I was 15 they quit hanging out with me. When I was 20 they were doing good with college, while I was in the humdrums of drugs. When I quit after I got arrested, convicted, and put on probation... they would see me around town and laugh at me because they "warned me what was going to happen". When shit went down and I got put on parole, I cleaned up completely when I was 25, I really didn't see them around anywhere.
Today I'm 29. I live a happily married life and I am still clean... oh and I've checked up on all those old "friends". Three of them have been in & out of prison for drugs (guess they should have heeded their own advice). One of them is still in prison because he just couldn't keep his hands off of his wife's throat. And the last one died in transit to the hospital because he was trying to knock off a store for his next fix, and was shot by police.
As I look back on my life... I really regret nothing. And I don't want to change anything either. If I was little again, I'd do things in exactly the same manner... because without those experiences, it wouldn't have made me the man that I am today.