When i was a child, i believed autopilot really worked like in the movie Airplane, that it was an inflatable dummy.
That hiding candy (or other things people wanted) was a universal property of grandmothers.
English is not my first language, but I had heard the expression “search all nooks and crannies”, but thought the last word was grannies - cranny is an unusual word.
Now,my own grandmother was in the habit of hiding candy for us to find. I thought the expression existed because all grannies hid things. Search all nooks and grannies!
I now have the hilarious image in my head of a toddler giving their granny a pat down (image of one in case the term isn’t familiar to everyone), thanks! 😂