Best way of explaining is using the gold analogy.
But I think explaining it to a person in his/her early teens will be quite diffiicult. Best to wait till the person reaches late teens and then explain
Yes ,it is so hard to explain to them especially if they are not interested to waste just like 2-4hours a day spending time to bitcoin .
But its easy to explain if the teenagers are openminded with business and money and they know how value each money that goes on their hands
It is very difficult to explain the childrens in there mind only is playing and they are not interested because they think only wasting time to them,but if you tell them slowly and explain them properly and spend a little time in study bitcoin and show them that there is a big benefits if you do bitcoin that strategy they will be interested,and teenagers is very easy to explain because teenagers are openminded and they want money if you introduced bitcoin to them that bitcoin can help them to get what they want and can earn money with it they will be interested and they will start research about it.