Youth is wasted on the young

When I first read this, I had a feeling that it means "They waste youth on their children(babies) = People are too much dedicated to their children", which is quite ridiculous.
Why isn't it "Youth is wasted by the young = Young people waste youth" and does "on" make some difference?

gu63)An aunt of mine has often said, "Youth is wasted on the young." This statement has stirred my curiosity for years. People usually smile when she says it, and I have always smiled, too. But I think I'm just now beginning to understand the meaning of the saying. I believe it is similar to a statement Thornton Wilder made in his play Our Town. Toward the end of the play Emily, one of the main characters, says, "I didn't realize that so much was going on and we never noticed!. ..Do any human beings ever realize life while they live it- every, every minute? Older people, looking back, can value youth, its real meaning and importance. But young people, while they are in the middle of youth, never fully realize what they have.

It's no different from "Nice clothes are wasted on me" or "Sarcasm is wasted on some people".

It's not a case of them wasting what they have been given. It's the fact that it is a waste of the time of the person doing it, to bother doing it to those people.

"Sarcasm is wasted on my brother". He doesn't waste sarcasm. It's a waste of my time being sarcastic towards my brother because he doesn't understand/appreciate it.

I fully understand what you mean, but in this passage, the writer is saying that young people are wasting their youth, not realizing it's true value. So not a third party is wasting his/her youth on young people, I guess. I'm a little more confused. - I typed in the remaining part.

ex)But young people, while they are in the middle of youth, never fully realize what they have.

I'm really sorry. After carefully thinking about it, I came to realize the following.
There's something like "youth", and we or the whole world possesses it or it is just there, but it's wasted on the young.
The owner related to youth doesn't have to be designated here. Your explanation was really helpful, Thank you!

You're right, but it still doesn't mean that the youth are wasting their youth. They might be doing lots of very worthwhile things and be of great benefit to society. However, the older we get, the more we look back on our younger years and realise that there were other things we might have done, or we might wish we were still capable of doing the things we could do fifty years earlier.

I know some people who are over 60 who now have the money and the time to travel the world, or take up skydiving, or attempt to climb Mount Everest. However, in their view, they are now too old to do this. If only they had had the money and the time when they were young, adventurous and fit! Wouldn't it be nice if they could now have the money and the time, but also have the vitality of youth to enable them to do these things?!

I don't agree that the writer was saying "young people are wasting their youth, not realizing it's true value. I agree with the second half, but not the first. They are not wasting their youth, they're just not fully appreciating it.

There is a big difference between something being wasted on someone, and someone wasting something.

The idea is usually that the energy and passion that youth have is only appreciated once you are old and have creaky bones and sore muscles and don't have the energy and pep you once had. A 5 year old child who constantly runs around the house and seems to have limitless energy can bring this sort of observation from an older person. The "youth" given to this child is wasted on him because he can not possibly appreciate what he has until it is lost.

The older person imagines what he could do with the vigor of youth if combined with the wisdom and experience that comes from age.