Yeah, me too. It started out pretty fun - and then I'd try to purposefully build up, say, my strength or woodcutting level or whatever. Eventually, I realized that's pretty much all RuneScape is - build up your level and destroy stuff. They should have a different way of fighting. When I was there, you just wait select something to attack and then automatically punch at your opponent every few seconds.
Maybe the repetitiveness, or maybe just too much waiting around letting the computer do the work or maybe something else really made me bored.
