People you may know list

Yeah, trying to figure out how people appear on your "you may know list" is a mystery sometimes. I see a lot of people that I do know on my list but I do not click them as FB friends. I like to keep my friends list small. Had to deny several friend request that came from total strangers. Wondering why hundreds of my old school classmates or business acquaintances aren't appearing. Most recommended are members of my sports clubs that I used to a member of, and people that I corresponded with by email over the past years.

FB uses social signals and it ranks them based upon a proprietary algorithms. It's relative, though (and recency weighs somewhat heavily). Hence this person may not have liked a bunch of things you like (recently), and someone else has, and has overtaken them in the algorithm. That person might be away from FB for any number of reasons (including Facebook jail), or just clicking on other stuff.