On the other hand, there is this "what doesn't kill you, makes you stronger". While this can be dismissed as dueling platitudes, one might also seriously think about worries of the "what's to become of me?" sort, as the needed callisthenics for the mind. Can a mind become irrationally too happy, and go out of shape ? Is the mention of a "playground" in the phrase "a devil's playground" point to the devil as a personal trainer working at a playground ?