Once you start a working on something, don't be afraid of failure and don't abandon it. People who work sincerely are the happiest.
The great question is not whether you have failed, but whether you are content with failure.
There is no loneliness greater than the loneliness of a failure. The failure is a stranger in his own house.
FAILURE, LONELINESS OF A FAILURE
Success needs no explanation. Failure does not have one that matters.
FAILURE, SUCCESS NEEDS NO EXPLANATION
Failure is instructive. The person who really thinks learns quite as much from his failures as from his successes.
FAILURE, FAILURE IS INTRUCTIVE