I figured it out when I was 7 when my parents inadvertently left the price tag on one of the gifts in the stocking.
I went to my parents and asked, “Santa doesn’t charge for his gifts, does he?”
That’s when they decided to come clean.
LOL.. I was annoying my mom about my brother trying to make me be bad so Santa wouldn’t come.. She blurted it out in anger. I in turn told the kids at school there was no Santa and they called me a liar. Ah.. the good old days.
I caught onto it when I was 7, too, but there was no single incident..... more just thinking about the impossibility of anyone visiting so many homes in one night. It all really started to bother me.... It just came to seem so implausible, and when I asked the question in a way that really put my parents on the spot, their looks to each other (as in “are we really going to have to lie about this”) gave it away.