Not a shred of evidence ...
More phrases
Effort only fully releases its reward after a person refuses to quit.
Never complain and never explain.
A good plan violently executed now is better than a perfect plan executed next week.
George S. Patton
Problems are not stop signs, they are guidelines.
Robert Schuller
Never give up, for that is just the place and time that the tide will turn.
Harriet Beecher Stowe
Quotes from the same author
To die quickly in one's eighth decade at the very top of one's powers is an enviable end, and not an occasion for mourning.
Brendan Gill