Presuming WoW is your first MMO of that type, 'theme park' as some people denote it. For most people probably won't happen again. It kind of goes for a lot of things. First time is great, then the next few times wouldn't be the same.
Only thing I can say is either don't play them or find one you enjoy through and through. Not look for a big one hit satisfaction that won't really happen nowadays due experience.