Explain Bitcoin to teenagers is actually not that hard, because teenagers always curious about things.
Bitcoin can be difficult to explain but people in youtube just making an interactive videos about bitcoin and trying to explain bitcoin through videos for the sake of this thing.
Yes interest is the important thing to learn and to teach something so you are right our new generation is technically really sharp they are born talented to get everything about crypto currency, if you will provide them a clue to search, in few minutes they will tell you something related bitcoin then even you will not be aware of, so I mean bitcoin can be teach to teenagers buy informing them about the importance of bitcoin and tell them using bitcoin they will be able to earn money even when they are students so it will enhance their passion and interest for crypto currency.