A nice thing happened quite a few years ago when we were traveling through France.
We were on an autoroute heading south, and we sped along, passing through the various toll booths. And each booth had a plastic hopper into which drivers would throw coins to pay the toll.
The plastic hoppers were a good idea, because they made the whole process of going through the booths much quicker. The machine would total up the coins, and if the amount was correct, it would whisk the driver through.
So my wife and I would sort through our coins and collect whatever was needed, ready for the next toll booth. I was driving a right hand drive car so I was on the 'wrong' side to reach into the hopper into which to throw the coins.
So my wife threw the coins into the hopper and off we sped to the next toll booth down the autoroute.
My younger daughter was very young at the time, perhaps three years old. She was intrigued with the way we deposited the coins, and asked whether she could do it at the next station.
And I remember so clearly her standing on the back seat and reaching over the front passenger seat with the handful of coins in her hand.
And she threw them.
But somehow we had misjudged what she had understood of the process.
And instead of throwing the coins into the hopper, she simply threw them out of the window.
Well we were low on coins; there was a line of traffic behind us eager to get through; and we had to get out and scrabble about on the ground for the lost coins.
I didn't think of it at the time, but I wonder what my daughter made of that?