Crypto currencies are the new Ataris - a few people have them and play them all the time, more people have them and play on the weekend. Most people have kind-of heard of them, but don't really have an interest (yet)

Then some Bill Gates-ish person will come along and create crypto for the masses and then everyone will have crypto and they'll forget what it was like to not have crypto.

Children will be born not understanding what it was like 'back in the day' when all you have was fiat.

When you talk about paper money they will laugh at the very concept.