You know how sometimes you're struck by a similarity between your own behaviour and your parents'? Like for instance, if I'm making a round of drinks for a few people, I know I'll forget which is which if they're in random order, so some years back I got into the habit of just arranging them alphabetically. OCD you may say, but it keeps me out of trouble. Moreover, in the modern world, you're more likely to know someone's given name than surname, so I alphabetise by given name. A year or two ago, I found out my mother does the very same thing. Surely that can't be very common?
Anyhow, more recently I was tickled to see this. This came at about the end of my song parody heyday, and a month or two after we were talking about Truss' book on PAN. I hadn't discussed either of those things with my mother, so it's a total coincidence ... or genetics!