Somewhere on the internet, I read about a number that reflects someone's lifetime running mileage or kilometrage (I forgot which, but I'll just use miles). It goes something like this: it's the largest integer N such that someone has run at least N runs of at least N miles. E.g. if I have run 20 or more runs of 20 miles or more but I have not run 21 or more runs of 21 miles or more, then my number is 20.
I mean it's not particularly interesting, but I was just reminded of it when I came across the Erdős number again and I just want resolution to this thing that's at the tip of my tongue.