I know what you're going through! Although I don't think I'm very old at 42. I lost one of my trailer wheel lugs for two weeks. The only thing I could remember was that I had picked it up "for a reason" and set it down "somewhere".
After an hour working at the mill, I happened to nod off...err..look down and there that sucker sat, in amongst a bunch of milling clamps, and chips on top of my tooling cabinet.