Other things your grandkids probably won’t understand:
Camera negatives (“You couldn’t just save your pictures?”)
Screen savers (“What’s the point of having your screen turn into a cartoon when you leave it alone for five minutes?”)
Tupperware and Tupperware parties (“Why would you have a party for something like that? You can get five Ziploc containers for a dollar at the supermarket”)
Videogame arcades (“Why would anyone come to a place to play videogames when they can just do it at home?”)
Porno mags (“It must’ve been weird to have to buy porn instead of just getting it on the internet”)
Video rental stores (“You actually had to drive to a store to rent a movie? What would you do when you were done with it? Drive back?”)
Libraries (Now that’s kinda’ scary, isn’t it?)
That America actually wouldn’t let gay people get married (maybe great-grandkids, but it’ll happen)