Come on it's a G A M E. Period. Do you actually understand what that means? It's about having fun. It's not about being perfect at what you do, or trying to be something you aren't and more so it is NOT trying to be/do what you don't want to be/do.
You can actually have fun in WoW, ignore the elitist jerks behaviour and do your own thing. WoW is one (if not the only one to this extend) of the MMORPGs where you can even play SOLO all the time and still enjoy the game.
If I where you, I'd be happy about having forgot about everything, because it means you can explore a lot of things again. It's like a "new" game, eh?
Oh and don't care about messing up groups - that normally takes more than one player (not counting a
really really really bad tank). Just try it.
After all WoW is pretty a pretty damn easy game.