I find that starting to look at things as black and white helps after you've left. Take all the grey matter out...your addict isn't any different than anyone else's addict. I feel like when we throw in all the grey area, we are making excuses for their behavior, or use bad experiences they've had as a reason for their using. Everyone needs to grow, don't beat yourself up for leaving. Be happy from a distance if he succeeds in living a clean life for himself.