I've kind of done a reverse "what did you find", and given something to be found.
I was fettling a bike on the stand, in the sun, out in the driveway.
I was using the rear bumper of the Land Rover as a shelf for tools.
Packed it all away.
Drove the car into town and back on an errand, and then noticed my 1/4 square drive ratchet sitting on the bumper, with one allen key mounted on it.
This had survived the journey into town and back.
The rack of other allen key bits was long gone.
Arse.
It's the single most important part of my toolkit.