My eldest (just a teenager) insisted that she had a crown on one of her molars when she was younger. I have zero recollection of this, and told her (nicely) that I would have remembered something like that, because crowns are expensive. This went on for several months.
Finally, she pulled out an older pic of herself.... With a crown in plain view.
Yes, I apologized. I think that's when I realized my memory really was that bad.