To tie together both the story you're replying to and your story, I had a good friend who at the age of around 14 was a little rebellious but still a smart guy with a good heart who wouldn't intentionally hurt other people.

He did sneak out of his home pretty frequently and also enjoyed smoking pot. I did the same thing - and from my parents' perspective, some scolding and discipline shaped me up somewhat. His mother (and I do feel bad for her, but I think she made the wrong call here) sent him to adolescent rehab for weed, and then subsequently sent him away to a group home for other kids with behavioral problems when he refused to quit (basically he continued to party on the weekends, we were around 16). Things went downhill fast as soon as he started staying in that group home. The people he hung out with were far worse than he had been up until that point and he had graduated to doing far more serious crimes. It got to a point where I started to cut ties with him, but we eventually became close again as he introduced me to heroin. Robbing people or stealing could never be part of the equation for me, no matter how desperate my need for opiates got, but at this point he had already tagged along doing that kind of stuff for fun with the group home kids. Needless to say, he robbed a woman with a paintball gun one night and attacked somebody who tried to defend her, seriously injuring them. He went to prison, got worse there, came out and continued down the same path. In and out. Last I heard he was back in lock up for another armed robbery, I suspect with so many offenses he'll be in for a long time.

I surely don't know the specifics and perhaps it's more complicated than I'm making it seem, but in my mind he just made a complete 180 as soon as his mother kicked him out of the house at 16. From my perspective she seemed like a solid parent and if I were her I think the move would have been simply to discipline him and shelter him for at least a couple more years. The friend group he had before being in foster care (IE, me and many of our friends) was so radically different from the folks he hung out with at the group home, I can't help but think things would have turned out differently for him if an authority figure that loved him would have just held onto him during those formative years.

Now I'm in recovery with a clean record and optimistic about the future (highly grateful to my parents for putting up with a lot of my bullshit), while he's in prison and from what I've seen isn't showing signs of changing any time soon. Things could totally still go south for me as well though - drug addiction really sucks and if left unchecked, principles, morals and goals go right out the window. I sympathize with how you look back at your ex bf though - nobody would believe it looking at him now, but I swear to god this guy I'm talking about was a caring, intelligent and driven one. I still think he is, honestly.