Neologism: Nerd osmosis
nerd osmosis - noun phrase - The phenomenon in which one picks up a small amount of knowledge about something one isn't particularly interested in because they spend time around other people who are and who talk about it a great deal. For example, it's possible to pick up a little knowledge of My Little Pony: Friendship Is Magic and its fandom without being a brony just because you are surrounded by people who are on a regular basis.