#58-1. If you are doing your best, you will not have time to worry about failure.
#58-2. It's not good enough that we do our best; sometimes we have to do what's required.
#58-3. It is more important to know where you are going than to get there quickly.
The first quote shows how we can reduce wasting time by focusing on doing our best. We do not really know the best we are capable of, new circumstances might bring out hidden talents and greater capabilities than what we thought we had.
The second reminds us that we might have to push ourselves beyond our known-current-best to achieve a particular goal in a given situation. The history of humankind tells us that anyone who did this either achieved the seemingly impossible or achieved many other greatly useful things on the way.
Periodically taking stock of the destination and the path instead of blindly running faster is recommended by the third quote. It is applicable to life in general, to problem-solving or troubleshooting situations and to our careers, an area of current interest for me.