nature or nurture

Me: Why don't you wear your Bullpup Football t-shirt today since there is a game tonight.
Him: OK.
Me: It's homecoming.
Him: I remember when I was in homecoming. Was that like two years ago?
Me: It was four years ago.
Him: WHAT??!!! I was only four years old when I did that? Where does time go? It seems like only two years ago.