I sure would teach my kids about Pokemon. I don't really like the new kind of storyline introduced in gen 7, I liked collecting badges more. So I'm going to show them how the main games looked in the past. I will also teach them about how to hack the saves and RAM of the games, because that's the most interesting part I think.
And maybe they want to play with my old Pokemon cards, currently those are doomed to collect dust at the attic...