I'm sure we've all had this happen to us: you see a character "for the first time ever!" -- and you know it must be very obscure, because you've never seen it before. Then you see it again soon.
Just happened to me with 扣. Saw it on an airplane (context was something like "请坐后扣好安全带"), and I was surprised that I've never seen as simple a character as 扣 before. Five minutes later, saw it on a headline on a paper someone was reading (something about US-China discussions, being 扣解, IIRC).