One must at least imagine Sisyphus happy, even under such circumstances

He might be happy, when his boulder gets to sink the reconstructed Ship of Theseus and he is finally rid of the thing that made him unhappy.

One must imagine the intimate number of people the bolder would kill if it smashed into it, and the ship can always be rebuilt, but is he happy, maybe if he pushes the bolder through an infinite amount of rooms killing an infinite amount of people.