Everyone has heard this a million times, but I bet you have never heard of the man who wrote it?
Reinhold Niebuhr, an otherwise unknown theologian penned The Serenity Prayer as recently as 1932, it sounds like something that would go back to ancient times.
Grant me the serenity to accept the things I cannot change,
Courage to change the things I can,
And wisdom to know the difference.
Epictetus had written something similar, likewise Shantideva, Solomon ibn Gabriol, Bartley and Schiller, so perhaps it does touch on a universal truth.
But is does take a little practice to master the serenity part:-