Generation Conflicts - are they simply natural?

Good evening!
This evening I had an interesting conversation with my son (21) about generation conflicts.

In the Belgian Ardennes, 2011.

When I was as old as he is now, there was a huge gap between the generations. The generation of my grandma didn't understand the generation of my mum, who let their kids run loose and wild (sex, drugs & rock & roll), and the generation of my mum didn't understand why my generation needed to lose themselves in sex, drugs & rock & roll. They didn't want to set us free; we simply took our chance and demanded our freedom.

It gave rise to many a conflict, I can tell you!

I have girlfriends of my own age (on the other side of 55) with children, and we all agree that we experience and enjoy warmer and more open relationships with our kids.

So what causes generation conflicts?
We came to the following conclusions:
- parents want their kids to avoid the mistakes they have made themselves
- parents want their kids to have a better life and take all opportunity for improvement
- kids want to do their own thing
- kids want to be able to make their own mistakes
- kids don't want their parents to meddle
- parents want kids to listen/behave/obey

Perhaps there are more causes, if you know any feel free to tell me.
But after tossing all these reasons into the mix, we came to the following idea:

* isn't all this conflict simply nature's way of making certain our kids want to pack their bags and start out on their own?

I like to watch the swans near my house.

They are caring parents! They look after their kids for more than a year, until the feathers have turned from brown to snowy white. They defend them hissing and spitting and threatening with their wings from dogs and humans. And then, from one day to the next, they are RUTHLESS.
I have witnessed young swans being chased straight into the path of racing cars by their parents. Away! Out of my sight! Move it! You are no longer wanted!
And absolutely no mercy.

Dogs are different, by the way. They live happily in the same house with their offspring, no problem. And cats, too, accept their own kids in the same house, but then cats are more individual anyway.

Still, we thought that it isn't natural for a young person to not want to move out at some stage.  If you stay (willingly!!!) beyond 25, you are either bone-lazy, or have no job thus no money, or there is a medical problem. And yes, there is a tiny number who stay out of altruism, because they feel their mum/dad/both parents cannot cope without them.

So. The next time my kid is stroppy, and I want to paste him/her behind the wallpaper (Dutch expression), I'll try to remember this conversation.