#88-1. Success seems to be largely a matter of hanging on after others have let go.
#88-2. The best way to judge an individual is by observing how he treats people who can do him absolutely no good.
#88-3. Satisfaction lies in the effort, not in the attainment.
Though the first is about persistence (or determination/going the extra mile) and the second is about handling people (or dignity/magnanimity), I think they are related in one aspect.
In today's result-oriented environment, many look at human relationships also with an RoI (return on investment) perspective. So helping someone who cannot be of "use" is unconventional, different from the crowd.
Similarly, everyone gives up at some point but many who have achieved something remarkable did it by not letting it go, not willing to agree to settle for less.
Somehow both seem to indicate a good kind of stubbornness.
The third quote happens to be from one of the world's best known "good stubborn" persons.