Mark Twain on youth

Dance like nobody’s watching; love like you’ve never been hurt. Sing like nobody’s listening; live like it’s heaven on earth.

A classic is something that everybody wants to have read and nobody wants to read.

Clothes make the man. Naked people have little or no influence on society.

When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around.
But when I got to be 21, I was astonished at how much the old man had learned in seven years.

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

Oscar Wilde1854–1900Phrases and Philosophies for the Use of the Young (1894)

I am not young enough to know everything.

J. M. Barrie1860–1937Often credited to Oscar Wilde