It trully is a waste of time. They will never understand it. Kids and teenagers don't want to hear about how a currency works or any of the details, they will find it boring, they can't be bothered, most adults can't, let alone kids and teens, let's just focus on making bitcoin work as expected by casual people.
No actually you are mistaken mate. Teenage is the best time to learn things because there is energy and eagerness to know new things.
You would never be able to explain bitcoins to old people, since they are stubborn but teenage just need a clue and they will in fact find themselves about it.