My first WoW memory is in Stranglethorn Vale. There are other events prior to STV that exist in some strange nebulous place in my mind, but Stranglethorn is the first event that I can really pin down. I was playing my very first character, my undead rogue on the Silver Hand server, trying to kill an elite alligator for the Excelsior quest. This was in December of '04, maybe January of '05. I was absolutely terrible at the game. I simply could not kill that alligator. Everyone I knew did it with no difficulty whatsoever, but I couldn't manage it at all.
The reason I couldn't kill it? I was spamming Sinister Strike while dual wielding white vendor-bought daggers. That was the day I decided I should learn how to play the game rather than hope my friends take pity on me and fly across Azeroth to kill elites for me. Now I'm here, on this site, doing this. That's one heck of a step up.