This was my answer on TS:
I did not do the Santa thing with mine; and the "Elf on a Shelf" really creeps me out. But I do remember my oldest when, at six y.o. he caught his grandmother (my MIL) lying to me. Later, he was talking to her on the phone, whispering under the dining room table, and he asked her why she lied to me. She repeatedly told him he was wrong and to just forget about it. He was dumbfounded. His spirit was so deflated by that incident. It was really sad to watch.