The Law of Unsorted Hardware:
If you need “N” identical pieces of hardware, and any quantity of unsorted hardware to be searched, you will find “N-1” pieces immediately. The “Nth” piece will never be found no matter how long you search.
Until You go and spend 45 minuets driving to the Hardware Store and buy the missing item and return to walk in the Shop and see the part that was missing on the other end of the Workbench.