I thought this could spark the odd amusing tale...
What I'm asking is what random memory returned to you unexpectedly which you hadn't thought about in absolutely ages?
For example, I was reading a book about the last 40 years of Ashes cricket in the bath just now and it referenced as an aside the 5-0 England Blackwash against the West Indes in 1984. Reading this sparked a memory that my uncle won a cricket bat signed by both teams from a one day international at Trent Bridge and that I used it to actually play cricket with with a tennis ball.
Amongst the players playing that day were Gordon Greenidge, Desmond Haynes, Ritchie Richardson, Viv Richards, Clive Lloyd, Malcolm Marshall, Michael Holding and Joel Garner. England had David Gower, Alan Lamb, Ian Botham and Mike Gatting in their side.
Those names won't mean much to you young uns but lets just say that it would probably fetch a tidy sum on eBay and that playing cricket with it wasn't the wisest thing to be doing with it (especially as my uncle didn't know)