Ah, makes me feel all nostalgic
Loved the whole idea of christmas, the magic, wonder etc.
I think I was about 11/12 when I found out. Totally bummed me out, I was horrified and it even made me question my belief in a God :p
Now, although still lovely, Christmas is just a bit too material and I always think if it's ok to lie to children for so long about something so big. Some parents REALLY get into it, my friends parents used to even put black footprints all over the floor from the chimney, the wife wasn't too impressed with that.
I think my favourite part was leaving out the cookies, milk and raw carrots for Santa and the reindeers, which my parents ate every year. Seeing the half eaten cookies in the morning...wow...no other feeling like it