Most people are committed to lack of commitment.

The average person puts only 25% of his energy and ability into his work. The world takes off its hat to those who put in more than 50% of their capacity, and stands on its head for those few and far between souls who devote 100%.

You have to be burning with an idea, or a problem, or a wrong that you want to right. If you're not passionate enough from the start, you'll never stick it out.

He who would learn to fly one day must first learn to stand and walk and run and climb and dance; one cannot fly into flying.