What my Dad was, is a very smart man who could see the writing on the wall, in the mid 60's and 70's. So he started a game with m. "I'm going to tell you something 'doesn't grow on trees'," he'd say. "You have to tell me why I'm wrong and why it does gow on trees." Being a kid, a contradiction game sounded like delicious fun to me, and I'd play enthusiastically.
"Don't slam the car door - car DON'T GROW ON TREES YOU KNOW!" he'd say. And I'd wade in.
"But they had to smelt the metal for the car, using coal or oil or wood. They all come from trees!"
"Eat all your vegetables. THEY DON'T GROW ON TREES YOU KNOW!"
"But trees had to be cleared for the farm where they grow, and they use fertiliser that should have been for trees, and the tools that farmer used are like cars, they had to burn something to make his tractor and plough!"
... and so on. I got tired of the game eventually, and stopped reacting as joyously. And there are only so many things to point out in life, before you realise, depressingly, that it all comes down to either million-year-old trees or contemporary trees.
A few years ago I was letting a friend's children wash dishes and play in the kitchen, and they broke a large plastic vegetable drainer I'd had for ages and repaired several times after minor mishaps, and when it finally broke beyond repair, I was very depressed. The children's mother spoke to me and said she'd buy another one, and I remember thinking about my father's game, and about the crude oil that would b processed to make the plastic, the oil/coal energy that would be used to form the new strainer, and the cost of transporting it around the world.
"But," I said, "They grow on trees, you know?"