I have well-developed mother's logic. 'If it's not there it must be somewhere else,' I say - to myself on this occasion as all my children have left home (finally) (temporarily).
The problem is that I have the habit of removing my bra in strange places. A limited number of strange places and, I should stress, all within the house rather than Sainsburys for example but nevertheless inconsistent placement.
After a fruitless search in all the obvious places and a few less likely it eventually turned up at the bottom of my wardrobe. My idea of tidying I seem to recall.