It can be tough for awhile but time erases things relatively quickly. You just have to move on to somewhere else and pretty soon your mind is otherwise occupied. I spent years on Ragnarok Online and years on WoW but breaking away wasn't really that hard. Actually, I find myself thinking of the chat-room where I spent my first years online even more. I wonder what those people are doing now. The toughest thing is feeling like you're wasting your investments of time and effort. I always become wealthy in any MMO I play, so leaving my cash and valuables behind sort of stings. I wish I could build interest on it while I'm away, that might entice me to come back at some point. Actually, I took some pretty strong pain medication a little while ago so I'm not really sure what I'm saying.
Here, I'm going to bed, so look at this. It's my favorite thing in the world right now.