“In youth it is the outward aspect of things that most engages us; while in age, thought or reflection is the predominating quality of the mind. Hence, youth is the time for poetry, and age is more inclined to philosophy. In practical affairs it is the same: a man shapes his resolutions in youth more by the impression that the outward world makes upon him; whereas, when he is old, it is thought that determines his actions.”

“What's a man's age? He must hurry more, that's all;
Cram in a day, what his youth took a year to hold:”

“To make good use of life, one should have in youth the experience of advanced years, and in old age the vigor of youth.”

“How oddly situated a man is apt to find himself at the age of thirty-eight! His youth belongs to the distant past. Yet the period of memory beginning with the end of youth and extending to the present has left him not a single vivid impression. And therefore he persists in feeling that nothing more than a fragile barrier separates him from his youth. He is forever hearing with the utmost clarity the sounds of this neighboring domain, but there is no way to penetrate the barrier.”

“Youth is the time of getting, middle age of improving, and old age of spending.”

“Just at the age 'twixt boy and youth,
When thought is speech, and speech is truth.”

“This world demands the qualities of youth; not a time of life but a state of mind, a temper of the will, a quality of the imagination, a predominance of courage over timidity, of the appetite for adventure over the life of ease.”

“Youth is not an age thing. It's a quality. Once you've had it, you never lose it.”

“In every young government strength is worth more than ancestral wisdom, but no government can remain young. As it grows older there is more respect for mature men than for old men. The leader who has build his career upon a basis of youth, loses youth. Like the old wolf, he tries to hide his disgrace; he keeps himself fit and affects the fearlessness and excess of a young man; but sooner or later time will make him a senator, then a corpse.”

“It does not pay a man to exist until the age of Methuselah by making his days indolent and useless. The more this is reflected upon, the more the reflector will desire to undertake meaningful and useful actions, the more they will have lived.”