Then Mists of Pandaria came out, and there was always something else to do. I had do dailies, or do heroic dungeons, or raid, or do dailies on my tailoring alt so I could make Royal Satchels. It wasn't that I hated pet battles, it was just that I never seemed to have time for them.
Then patch 5.3 came out. I wasn't too thrilled with Battlefield Barrens, and you can only run Raid Finder Throne of Thunder so many times before it gets a little old. Thus, I decided to finally level that pandaren shaman that I had sitting in Westfall for months, and as I leveled her, I figured I might as well have her do some pet battles.
Here it is, a few weeks later. I'm up to 5 level 25 pets, 370 pet achievement points, and I've been parking alts in Felwood, Silithus, and even Gnomeregan in hopes of grabbing rare pets.
Do I regret not starting pet battles earlier? I don't think I do, really. I had fun with what I was doing before, and I'm really glad pet battles were here to give me a backup when I needed a break from those things. That said, I do sort of wish I had gotten into this a few months earlier, because now I have to wait half a year for that dang Snowy Owl.
What about you? Whether it's been in this expansion or just in general, is there some part of the game it took you a while to get into?