I almost ignored the invite to the group but I decided to see what they were on about, it was basically a group for posting ponified meme's and chatting bout them (which I found funny even though I wasn't a brony). At one point a friend put up a link to an episode (mare do-well) and was talking about the beginning (where they decide RBD is most awesome pony).
I watched the bit the guy was talking about and then kept watching (as it was the full episode linked) I started skipping bits, it wasn't making much sense to me at all. Eventually I decided I was going to go back and watch all the episodes up to that episode so it made more sense.
Little did I realise I had watched Episode 8 in season 2. So by the time I made it back to that episode, not only did it make sense, but I was completely hooked on the show.
