You know when you have items you don't use often but you keep them in the same place, sometimes for years?  So even though you may not need oh.... that lace tablecloth, the champagne glasses, the tiny jewelry bead pliers, the shredded paper for gift boxes or the 20 foot extension cord except once in a blue moon, you know where it is.

But then you cleaned out a closet, drawer or cupboard and decided to organize it and put that item somewhere else.  Or you used it and thought "I know a better place to keep this..."  or you just decided that original random spot was weird or dumb and you need to keep the item somewhere where you will remember instantly it's there because it just makes more sense.

So then the next time you need it, you absolutely cannot find it.   Because, it's not where you kept it forever... because you stupidly thought you would move it to a 'better' spot.