I've gotten some strange ones too. Usually friends of friends who seem to want to collect as many as they can. I usually delete them, with a couple of exceptions. I have an acquaintance from my HS days; she was very good friends with some of my close friends, but I only knew her to hang out with the whole group. Her partner friended me, and I accepted, even though weíve never met.
Another however, I deleted. It was from a 14 year old boy, and initially he had no friends but I figured he HAD to be friends with someone I knew. I was curious, so I left it and checked after some time had gone by. Sure enough he was friends with some of mine, but as he lived in another state, and I had no clue what his relationship to my friends actually is Ė family, friend or whatnot, and his age, I wasnít at all comfortable accepting his request so I deleted it.
I have also gotten some from people in HS maybe I didnít know all that well back then, but I accepted. The only one I didnít I suspect was maybe sent in error since even though we went to school from grades 7-12 I donít know that I ever spoke a single word to him.