Ahmet Ülkü's Key Ideas from On the Shortness of Life
by Seneca

"You are living as if destined to live forever; your own frailty never occurs to you; you don't notice how much time has already passed, but squander it as though you had a full and overflowing supply - though all the while that very day which you are devoting to somebody or something may be your last. You act like mortals in all that you fear, and like immortals in all that you desire."

"... learning how to live takes a whole life, and, which may surprise you more, it takes a whole life to learn how to die"

"So you must not think a man has lived long because he has white hair and wrinkles: he has not lived long, just existed long."

"No one will bring back the years; no one will restore you to yourself. Life will follow the path it began to take, and will neither reverse nor check its course. It will cause no commotion to remind you of its swiftness, but glide on quietly. As it started out on its first day, so it will run on, nowhere pausing or turning aside. What will be the outcome? You have been preoccupied while life hastens on. Meanwhile death will arrive, and you have no choice in making yourself available for that."

"Call to mind what work you have achieved in such a long life; how many have plundered your life when you were unaware of your loses; how much you have lost through groundless sorrow, foolish joy, greedy desire, the seductions of society; how little of your own was left to you. You will realize that you are dying prematurely."