Undertake something that is ...

Undertake something that is difficult; it will do you good. Unless you try to do something beyond what you have already mastered, you will never grow.
Undertake something that is difficult; it will do you good. Unless you try to do something beyond what you have already mastered, you will never grow.
 Ronald Osborne

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