Having a coffee in Paris in 1995 when I looked up and realised the lady at the next table was my rather tasty English teacher at High School here in Australia back in the 70s! Amazingly, she remembered me as well.
Most bizarre of all was an encounter with a group of Australian Rules footballers from my home town here (Geelong) on an end of season trip to the UK who's bus had played up on the M6 so the driver dropped them in the town centre of Rugby where I happened to be living at the time. Anyway, imagine my surprise when I pop into town and find half the guys I played Under-15 footy with 15 years earlier wandering around looking for a pub at 10am on a Saturday!! I think the first exchange went something like "farckin'ell Dave ya old bastard, what are you doing here?", "errr.. I live here, what's your excuse!!??"