I work with a guy similar to that. 36 years old, lives with his gamer roommate and two cats, and every single thing he talks about pertains to MMOs. Literally every conversation I have with him will quickly revert back to what he's done in EQ2, or how his guild is doing in WoW, or what he's heard about SWTOR, how he had to borrow cash from his parents to register his car because he blew his entire paycheck on EQ2 crap and having multiple active MMO accounts...etc etc. I think I could honestly say that MMOs have destroyed his life, and he's enjoyed it.

When I feel like I'm getting tired of an MMO, or it's taking up too much of my free time, and I decide to quit, he's what I think about. His life (or lack there of) is the biggest motivator to just log off and walk away. Since knowing him, it's been quite easy for me to just log out and not think about it again.