At fifteen, my mind was bent on learning.
At thirty, I stood firm.
At forty, I had no doubts.
At fifty, I knew the decrees of Heaven.
At sixty, my ear was receptive to truth.
At seventy, I could follow my heart's desires without sin.
From the loving example of one family a whole State may become loving, and from its courtesies, courteous; while from the ambition and perverseness of the one man the whole State may be thrown into rebellious disorder. Such is the nature of influence.
To know, is to know that you know nothing. That is the meaning of true knowledge. When you say something, say what you know. When you don't know something, say you don't know. That is knowledge.
First and foremost, be faithful to your superiors, keep all promises, refuse the friendship of all who are not like you; and if you have made a mistake, do not be afraid of admitting the fact and amending your ways.
A youth is to be regarded with respect. How do we know that his future will not be equal to our present? If he reach the age of forty or fifty, and has not made himself heard of, then indeed he will not be worth being regarded with respect.