Re Sandra's Theory of Lost Stuff: Thanks: that's a rather better version than my father's (roughly "The best way of finding something is to buy another one"). My personal meta-theory is that, once I've given in and bought the replacement, I cease looking for the offending item in all the same wrong places, and happenstance can get a look-in.

An alternative is to inadvertently goad Herself into looking for said item as well,* and resign myself to being called an idiot. That was the basis of a subplot in one of the Upstart Crow episodes.

* She will have a different set of wrong places, and one of them may well be right. It's analogous to profredding for tyops.