No, not the big question. I'm guessing that many readers of this blog had their 5-year-olds come to them with good arguments about the top land-speed of reindeer, their dense bones which would preclude flight, the exact number of houses in North America--let alone in the rest of the world where, curiously, many cultures have a different conception of a night-time gift giver. Or, if your kid has a strong inclination toward fairness, she noted that while some of her friends got huge gifts from Santa, her stocking inclined mostly toward gum and toothbrushes (I don't think my parents wanted Santa taking credit for the good stuff!).
Since my family was firmly in the gum-and-toothbrushes category, any Santa belief ended quite early. In second grade, my class was supposed to write letters to Santa, which would then be answered. I wrote a letter saying this was a stupid exercise since he didn't exist. The letter I got back said I sounded like a smart little girl. I'm not sure if that was a good thing.
Anyway, the question is what to tell kids to say to other kids about Santa. While gifted kids can figure things out quickly, they're not always that good at social niceties, or see the point of white lies. It's wrong to lie to people, right? So if you've got a little Santa truther, how do talk him through this social navigation, particularly if all his friends at school or church are still at the age where it's fun to believe? (There's a broader take on the Santa issue, from the child development perspective, talked about in this article here). I'd love to hear how you all handled this issue.