So so true. We've all done it, cleaned the spanners, put everything away, mug of coffee in hand feeling pleased with yourself, when you glance at the workbench and there's a bloody nut/bolt/o ring you forgot to put back! And it's not the last thing you just fitted,oh no, its buried behind the worst knuckle shredding most bastard inaccessable spot on the machine, that despite contorting yourself like a yoga master hooked up to a h.t. lead,is just out of fingers reach. And after pulling it all to bits and putting it back together again, you figure out how it could have been fixed in 5 seconds flat.