Heavens no, Dear Reader; if he's a drugged out, zombie brained, frat cat now there's a fair chance it can be outgrown. He's only in his early 20's. There are plenty of ex-druggies and partyers who, as time goes by, become less interested and consumed with this lifestyle. Some go on to greatness: Johnny Cash, Anthony Hopkins, Robert Downey Jr. Some go on to heal themselves but destroy other peoples lives: George Bush, 43.
Still, it seems this guy you speak of has shown an early and steady proclivity for the bong and beer lifestyle. He will need to find other ways to 'decompress' or more importantly figure out what he's escaping from. Now I'm no Dr. Drew, though I do run a Celebrity Rehab Clinic out of my apartment in Brooklyn, but if I were you, I wouldn't be throwing all my eggs in this guy's basket. If you're dating your town's Kurt Cobain or Lindsay it could be a painful and frustrating road for you. Be supportive, but be smart; a 22 year-old drunk guy is reasonable, a grown drunk is as vile as THIS piece of Hasselhoff
Funny Guy
He might very well grow out of it, but do you really want to be there for the ride. It's one thing to date a party guy, and enjoy dating that party guy, or tomeet and date an ex party guy later in life. But you know this guy as a druggy party guy. You don't know a person when they spend that much time high, you know the drugs and you know the alchohol, how do know you'll even like him sober. I'm not saying you won't, but if you stick it out expect to be dating a completely different guy someday, and I'm talking more than just the natural growth and change of a person, which is difficult enough for people to deal with sometimes.