Life is a checkerboard, and ...

Life is a checkerboard, and the player opposite you is time. If you hesitate before moving, or neglect to move promptly, your men will be wiped off the board by time. You are playing against a partner who will not tolerate indecision!
Life is a checkerboard, and the player opposite you is time. If you hesitate before moving, or neglect to move promptly, your men will be wiped off the board by time. You are playing against a partner who will not tolerate indecision!

Quotes from the same author

Friendship, like credit, is highest when it is not used.
Never explain - your friends do not need it and your enemies will not believe you anyway.
A little more persistence, a little more effort, and what seemed hopeless failure may turn to glorious success.
There is no failure except in no longer trying.
A failure is a man who has blundered but is not capable of cashing in on the experience.