When I was watching "Kids" for the first time, I was thinking: are there really kids living like this? The answer is probably yes. It seems like they don't know any better. At the end of the movie at least one of the characters seems to realise what he was doing with his life, and most likely learned from his experience(s).
The movie was a real eye-opener. Many (parents, for example) will label it a "difficult" movie because of all the violence and the sex scenes... granted, not for all eyes & ears. But the fact is, things like scenes in this movie happen every day, somewhere on the planet. Don't close your eyes for them.
The dynamics of this movie really made me think of what makes personae in a movie tick... It's not just an action movie, or a thriller, or a science fiction movie. You really zoom in on the characters (and their actions, motives, passions) more than anything else.
And as long as you're reading: if you like the music in the movie, I'd suggest you buy the excellent soundtrack, mostly containing tracks by The Folk Implosion.