We really like the St Francis of Assisi Serenity Prayer:
Give us grace to accept with serenity
the things that cannot be changed,
Courage to change the things
which should (can) be changed,
and the Wisdom to distinguish
the one from the other.
Too many businesses spend wasteless energy and resources on trying to change things that simply cannot be changed, instead they should focus on changing those things that need to be changed and that can be changed.