Seneca

“Leisure without books is death, and burial of a man alive.”
― Seneca

“Enjoy present pleasures in such a way as not to injure future ones.”
― Seneca, Letters from a Stoic

“As long as you live, keep learning how to live.”
― Seneca

“Sometimes even to live is an act of courage.”
― Seneca

“Begin at once to live, and count each separate day as a separate life.”
― Seneca

“Hang on to your youthful enthusiasms -- you’ll be able to use them better when you’re older.”
― Seneca

“True happiness is to enjoy the present, without anxious dependence upon the future, not to amuse ourselves with either hopes or fears but to rest satisfied with what we have, which is sufficient, for he that is so wants nothing. The greatest blessings of mankind are within us and within our reach. A wise man is content with his lot, whatever it may be, without wishing for what he has not.”
― Seneca

“Most powerful is he who has himself in his own power.”
― Seneca

“Life is like a play: it's not the length, but the excellence of the acting that matters.”
― Seneca

“Luck is what happens when preparation meets opportunity.”
― Seneca

“All cruelty springs from weakness.”
― Seneca, Seneca's Morals: Of a Happy Life, Benefits, Anger and Clemency

“Difficulties strengthen the mind, as labor does the body.”
― Seneca

“Non est ad astra mollis e terris via" - "There is no easy way from the earth to the stars.”
― Seneca

“As is a tale, so is life: not how long it is, but how good it is, is what matters.”
― Seneca

“You act like mortals in all that you fear, and like immortals in all that you desire.”
― Seneca, On the Shortness of Life

“We suffer more often in imagination than in reality.”
― Seneca

“It is not that we have so little time but that we lose so much. ... The life we receive is not short but we make it so; we are not ill provided but use what we have wastefully.”
― Seneca, On the Shortness of Life

“It is not the man who has too little, but the man who craves more, that is poor.”
― Seneca