Sisyphus was famed as the craftiest of men.

As a punishment from the gods for his trickery, Sisyphus was made to roll a huge rock up a steep hill, but before he could reach the top of the hill, the rock would always roll back down, forcing him to begin again.  The maddening nature of the punishment was reserved for Sisyphus due to his hubristic belief that his cleverness surpassed that of Zeus.

But, “one must imagine Sisyphus happy” as “The struggle itself towards the heights is enough to fill a man’s heart.”