Facebook algorithm is magic

One of the recommended friends gave a housemate I had from 8 years ago. We never had any mutual friends or anything. I didn't even know he has Facebook. Merely just living at the same place at the same time for a year. I was in uni, he was working. Nothing similar.

He's not in any of my socmed or contact list.

Facebook algorithm is absolute magic...

Magic? Or creepy and invasive?

facebook found my dad even when i made every effort to not add any family members on my facebook nor do i have mutual friends with him.