I remember my mother giving me "the talk" that Santa wasn't real, but I already knew by that point. I don't remember finding out, or if I ever believed it in the first place. Possibly my older sister told me and I just don't recall it. Anyway, I responded to Mom, "I know," and MOM was upset.
"What do you mean, you know?? Who told you?!"
Like, did you WANT me to be upset, Mom? LOL