It has been claimed that nothing is more important for achieving success than perseverance. Talent without perseverance is no guarantee of success. There are millions of talented failures around the world. Not even genius will succeed without perseverance.
A former fiancé once gave me a notebook which had a picture attached to the cover. It was a depiction of a large bird swallowing a frog while the frog was choking the bird by the throat. The caption read, 'Never, Ever, Ever Give Up'. That admonition is attributed to Winston Churchill.
If one takes this admonition to heart, what can they do to bolster their fortitude?
I believe the best answer was given by Nietzsche who pointed out that the key to bearing any 'how' is to have a strong enough 'why'.
A powerful reason for doing something will bear one along during difficult periods of resistance and setbacks.