Meaning of this oscar wilde quote?

Question

"The old believe everything, the middle-aged suspect everything, the young know everything."

Answer 1

Oscar Wilde was a quirky guy to say the least. My understanding of the quote is that he is evaluating the state of mind of different aged people. With old people, you can usually tell them anything and they will generally believe it no matter how ridiculous. They have become aged, indifferent, and very gullible. Middle aged people will here something and be very skeptical, almost to the point of not believing anything, even things that might be blatantly obvious. and as we all know, youth think that they know everything, regardless of how little they actually know on the subject. Wilde shows through this quote that in all stages of life, we never really gain stability of thought or use our minds to their full potential.

Answer 2

Wilde always said both more and less than he actually meant.  

On the surface, it all looks true, and even obvious.

But it isn't.  

The young don't know everything, the middle-aged seem suspicious because they're starting to question what they are told, and the old appear to believe everything because most of what they are told they are so indifferent about, they don't care if it is true or not and merely pretend to believe it to get along with the people that say it.

Answer 3

Kind of self-explanatory:

Old people are gullible, thinking people will be kind to them.

Middle-aged are in the middle of worldly life, so everyone wants to get something from them, so they assume everyone has a selfish motive.

Young people think they know better how to make a better world.  They are arrogant out of ignorance. They need experience to make them humble.