In REBT we emphasize several values, such as knowing yourself, being responsible for your actions, and being tolerant of yourself when you make mistakes.
Persistence is another.
It can be one of your most important values to follow. Once you've decided on a goal, you believe it will gain you happiness and less misery, and it probably will. Let's say that you get started toward your goal, then get frustrated, become hesitant, and quit. That's hardly a prescription for healthy and happy living. Often you may give up when you see others who have it easier than you do because of their greater intelligence, talent, beauty or fortune.