[identity profile] seth ellis (from livejournal.com) 2015-11-01 03:00 am (UTC)(link)
My Dutch grandmother used to put butter on PB&Js when I was small, and weirded me the hell out. Two kinds of butter! Madness!

ETA: For the completion of the research, I'm 45 and only experienced butter on PB&J's at my grandmother's house.
Edited 2015-11-01 14:51 (UTC)