All non-trivial abstractions, ...
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
Listen to your customers, not your competitors.
Joel Spolsky
So if you want to get things done, you positively have to understand at any given point in time what is the most important thing to get done right now and if you're not doing it, you're not making progress at the fastest possible rate.
Joel Spolsky