An old friend liked a post on my new secret FB account, how did they find me?

I stopped using my old FB account a couple years ago, my old friend is fb friends with that one. I made a new account with a name that is similar to mine but slightly different, I use it for talking in groups and with friends about some stuff that is hard to understand and I don't want general people I know irl to see. This week I posted in that account about my pet that is unwell. This old …

account find friends mine name old privacy secret talking