Happy belated birthday, Amy.
When I was 3, I asked my father how old he was after he blew out the candles on his cake. He smiled at me as he said he was 21.
Next year I was in kindergarten and I again asked my father how old he was on his birthday. He said 21, again.
Thing is I had learnt to count in the interim, so I wasn't going to let this slide. I remember arguing vehemently that he must be 22 as he was 21 last year. He agreed. "You caught me out with your education. I'm actually 22." he admitted.
I believed that up until his next birthday, when large celebrations were had for his 50th.