Fun fact: I deleted Facebook for roughly 7 years, much of my 20s and early 30s. I got back on and added idk 100-200 friends, mostly family and such. My suggested friends are mostly like HS people because I live around where I grew up. About a year into having the account back, I saw this woman from a state I used to live in on my suggested friends list. She seemed VERY familiar but I had no idea why. I clicked around more, scrolled thru old profile pics. It clicked: she was a woman who I met once for a date about a decade prior. I had met her on OKCupid, an app I deleted in literally 2015 along with the account. One single date after very, very little back/forth. I clicked back and there were two other women who I had also met in exactly the same manner in the exact same year. Have never seen them pop up again since.