After all, what is life but a mixture of unsolved problems, ambiguous victories, and amorphous defeats?

Abdul Kalam
in Wings of Fire

A slightly more complete quote:
Looking back on my days as a young scientist, I am aware that one of the most constant and powerful urges I experienced was my desire to be more than what I was at that moment. I desired to feel more, learn more, express more. I desired to grow, improve, purify, expand. I never used any outside influence to advance my career. All I had was the inner urge to seek more within myself. The key to my motivation has always been to look at how far I had still to go rather than how far I had come. After all, what is life but a mixture of unsolved problems, ambiguous victories, and amorphous defeats?