The heights by great men reached and kept were not attained by sudden flight, but they, while their companions slept, were toiling upward in the night.
I've come to embrace the notion that I haven't done enough in my life. I've come to confirm that one's title, even a title like president of the United States, says very little about how well one's life has been led. No matter how much you've done or how successful you've been, there's always more to do, always more to learn, and always more to achieve.
There is no success without sacrifice. If you succeed without sacrifice it is because someone has suffered before you. If you sacrifice without success it is because someone will succeed after.
But man is a fickle and disreputable creature and perhaps, like a chess-player, is interested in the process of attaining his goal rather than the goal itself.