So long as he's able to balance his time as a trainer with his responsibilities in the real world, I don't see a reason to give up the games. I'm 25, married, work full-time and have a comfortable life. I own (in one form or another) every single main-series game up to gen4 + Conquest; and i'm working on grabbing B/W 1 and 2 as well as X/Y when they come out. The point is balance; so long as it doesn't consume his life (Unless he's a professional making a living off that shit, in which case go man go!), let him have his fun.

I feel like OP is a buzzkill. You're never too old for pokemon and you should know that :D

Whaaaaat?

I'm 24 and I'm still working on getting some badges so let him know he doesn't have to retire. I'm up for a battle any time as well.

Pokémon is more then just a game...it's a way of life.

Has anyone checked her name yet?

Depending on what you mean by "laughed", he has a right to be pissed at your lack of maturity. What does age have anything to do with liking something? "I'm a grown up because I don't like kiddy stuff" is the reasoning of a 5-year-old :P I love Pokemon, but this has nothing to do with Pokemon, it has to do with letting people enjoy whatever they want regardless of age.

Tell him to go train on Mt. Silver for three years.....

I FEEL YOUR PAIN OP!!

You never go back from being a Pokemon trainer. You can take breaks for a year, or maybe more. But you can NEVER go back.