Why do 21 year old sons treat thier mothers as if they don't understand anything?

[Marge]

Even if I did the same at that age! Thought I knew everything! Until I had my 21 year old son.

[Marge]

I look at it like this - they will have kids of their own one day, and those kids will grow up to be know it all teens-20 somethings and will then be giving them the grief. Is that like karma? ;o)

[Robin B]

It's a natural arrogance. I think it's called 'growing up' or 'the difficult years'

The things that you did when you were 21 are not the same things as a young person 21 years old today.
Everybody seems to learn the 'hard way'

[Matty]

Because each generation learns more information than the last, and the younger generation feel as though their parents know nothing compared to them. It's not always true, but quite often is. The older generation also hold a large amount of information which is no longer of use to modern life, while the new generation are pr0 with the 'ole twitter and facebook. The next generation, however, will laugh in the face of the twitter experts.

Let's be honest, you don't learn much from the age of 21 onwards compared to previously and it's only human to start forgetting the stuff you learned from the moment you stopped learning it. Unless you work in a very academically challenging area or hobby, you're unlikely to know as much as you knew on the day you left school/college/university.

[Kernow Lady]

They are still at it at 36.
Going through it now.