I have a theory that when you put a tool down then go to get it again, your brain puts a cutout shape of that tool in the olfactory centre so when you look at it on the bench, (right where you left it) the shape cancels the vision and you keep looking....finally the cut out fades and you go "Christ its right where I left it!" after doing 20 laps of all the spots it might be.. feel free to own this this theory