For years I have been saying "またまた" for "see you" to Japanese people I meet. Well at least half the time, since I also often say "またね".
But only tonight for the first time did anybody pick me up on it and tell me it's not right! I arrived yesterday in Okinawa for the first time.
So I know a more "proper" way to say it is "じゃあまた" and considered "またね" as a bit more informal. I had always thought I picked up "またまた" from a backpacker I met either at home in Australia or in a hostel in some third country. Possibly even from staff in a hostel in Japan.
So is it something I just imagined or made up myself? Or is it actually used as slang by young people in some part of Japan?