There are things we do every day that our grandkids will see as insane. They'll joke about how their grandparents (all of us) lived in the stone age. I mean, just look at how they lived.
"They used small gasoline engines to do yard work; mowing lawns, edging, etc. Like, handheld machines that harness a rapid sequence of literal explosions, and spit out noxious fumes and a LOT of noise. Just so they could cut grass to look pretty."
Most of our grandkids won't have personal lawns anymore than most of us have farms, and the gasoline engine will seem... just bonkers. Downright irresponsible. They'll likely have communal parks maintained by a quiet, robotic, electric fleet.
"I heard my grandpa used to eat meat made from REAL animals at *every* meal. And the way they grew and bred animals was mass torture, keeping pigs and cows in small, filthy cages, pumped full of drugs to keep them alive just long enough to have some meat on their bones. Just so they could have a pulled pork sandwich when they wanted."
Our grandkids will eat proteins that didn't come from animals, at least not in the sense that we do. They might eat plant-based protein, or lab grown bio-identical meat from cells cultured to grow a "steak" that was never part of an animal. They might eat "eggs" and other proteins secreted from genetically engineered yeast. Maybe they'll eat protein from insects, which have a minuscule fraction of the environmental impact as large animals, are easier to raise and breed, are a vastly lower ethical dilemma, and in some ways are just better protein.
The industrial meat and dairy industry will look as barbaric to our grandkids as human slavery does to us.
"Our grandparents, almost all of them, used to drive cars manually, starting when they were teenagers, and piloting cars as large as a couple tons. They had to pass a test basically once, and then they could drive whatever they wanted. And of course tens of thousands of people were killed and maimed and disabled in high-speed crashes, almost all of them from pilot error."
Our grandkids won't "drive a car" any more than most of us ride and reign horses. It'll be a romantic throwback activity, probably reserved for the rich, who have the time, money, and designated space to "drive" a large and dangerous vehicle.
"And get this... in the 20th century, almost nobody had anything that we'd recognize as the Internet. If they wanted to learn something new, they had to go to a physical library, a place that kept all the books. Even their phones had to be wired down in their house, and everybody at a house would use the same phone. So you wouldn't call, like, your friend Johnny. You'd call Johnny's house, and if somebody else answered the phone, you'd have to just ask if Johnny was there and if you could talk to him."
That part will just be incomprehensible to our grandkids.
Believe it or not, compared to your grandkids, we all live in the stone age.