I do this with pretty much everyone that I’ve met after college. Because in college I remembered ages of my friends relative to my own, so I remember who is roughly a year older or younger than me. My family I remember from the years they were born, but most everyone else I probably only remember the first age I ever heard from them. I think I’m going to be that adult who insults kids by remembering their age wrong, and kids when they’re young enough go by fractions of a year too.