I was between 8 and 10 I think. I could have been a little younger. I do remember the day though. I asked my mom, and she told me the truth. I was a little p.o. ed to say the least. More so that she was lieing to me for all those years, than they fact that he wasn't real lol.
Its nice having kids now, you still get to experience the magic of Christmas through them.
To me the excitement of Christmas morning is watching them go bonkers.