I've always likened myself to a coin-sorter. Coins of all sizes are indiscriminately dumped in. The contraption need only be shaken lightly, and the coins fall into place.
Trouble arises when any reasonable combination of the following happens:
(1) too many coins are dumped in at once,
(2) the contraption is shaken too quickly as to slow down the sorting,
(3) we encounter coins of different currencies that are of varying value, but similarly sized,
(4) when foreign objects that are not currency are introduced into the system, and finally
(5) when no shaking occurs.
I am a simple contraption. All I want is to function optimally.