I worked out that FC didn't exist age about 5 - my parents did all they could to make Christmas magic, and they certainly didn't tell me - but even at that age I was a complete cynic.
This week DD has been questioning it - last week it was the Tooth Fairy, and she just said "mummy, I know the tooth fairy is just you and dad!" I queried how she 'knew' this and she said that "if something doesn't make sense, it's probably a lie". Fair.
Today:
DD: "tell me the truth does Father Christmas exist?"
Me: "what do you think, I mean, you met him last year, did he feel like the real Santa?"
DD: "well yes, but it could have been an actor"
Me: "well Christmas is the most magical time of year, so if there are magical things, Christmas is the time to expect them".
Question: do I tell her, yes, she's right - and try to bring her into keeping the secret from all her pals. Or do I bare-faced lie to her to keep a little bit more magic alive for a little longer?
Notably: though I worked it out very young, I still LOVED and continue to LOVE Christmas, it really IS magic to me, even aged 44.