I guess in a way I always knew, but I liked to pretend otherwise. I know that when I was around two or three in the first house I lived in, I would try to wait up with my brother to watch for Santa, but we never made it. My mom told my brother when he was like five which I think is WAAAY to early, but he'd taunt me with it every so often, and I guess that kind of sped things up. I can't remember when it actually was, but my dad came clean when I was 12, and then we laughed about it cause we all knew by then I knew, lol.