hibernating six line?

So I have a sixline wrasse that went missing over two months ago. I checked my overflows, sump, the floor....nothing. I accepted that my third sixline had disappeared and moved on. Well last night when I was feeding, guess who was out swimming around? Yep, over two months missing and last night he is back and swimming around as if nothing happened. I know somebody else this happened to as well, although his only vanished for a month.

Anyone ever seen this? Do they hibernate or something? This is crazy. I couldn't find anything on the internet really...