Bear, Wylie Post may have sounded quite cogent in this regard to most. To me it's rubbish. And I'll stake my reputation as being the person in this household to go to for finding things.
I do not always find them first pass or even second or third. I just don't give up. Eventually something will prompt me that "I've not looked here before" and I find what I am looking for. That is if I don't discover it in a place I looked at and simply didn't connect what I saw with what I was looking for. And this is after my partner has looked for an hour or so.
If you're looking for something, and you have reason to believe it is within a specific volume, then don't stop looking. Expanding the boundaries is usually good for a break. But most of the time the prize is within the original search volume.
Of course, it helps to search the entire likely volume, repeatedly, before branching out very far. The key is, "Don't give up until the prize is in your hands." Giving up guarantees you will never find the prize.