in my experience it's the kids who used to believe in FC and suddenly find out it's not true that are more likely to go around telling other children because they feel powerful and all of a sudden 'older' than the believers. (Maybe also in some cases because they feel a bit sad/ambivalent about it.)
^This.
I have never believed in Santa, it was never a big deal. I never 'told' anyone. Because it wasn't a massive secret. Just like, in my house we didn't have soda or artificial colourants, I knew other kids did: that was them, this was us.
I think it's only people who 'do' Santa who think it's this huge big deal. I was raised as an atheist and I understood from very young that other people went to church, we didn't, and we didn't talk about that as it might hurt their feelings.
Also, I think many of you who 'do' FC don't appreciate the excitement that Christmas can have for those who don't. We always knew our parents bought our presents, but we never knew when or what. We just knew the big walk-in wardrobe was off-limits from the end of November. It was thrilling to imagine what surprises they were planning for us - and us for them!
On 'the eve of Christmas Eve' (aka the 23rd) my dad would bring all the wrapped presents down in the evening, after we'd decorated the tree. I loved that tree - it was so tacky!
It was hugely exciting watching him pile up presents and arrange them around the tree. We then had a whole day (Xmas Eve) of waiting and guessing before opening presents on Christmas itself. Those childhood experiences are magical in my memory, because they were all about mutual giving of gifts.
Also, if you 'do' FC, where do your presents from your children come from? Or don't they get you any?
If not, that's so sad - a huge amount of the joy of Christmas for me was watching my mum open the rubbishy picture frame I'd make in art class or the chocolate or earrings I'd saved my pocket money to buy. Christmas was about giving, not just getting.