You’ll likely know The Serenity Prayer: God, grant me the serenity to accept the things I cannot change; the courage to change the things I can; and the wisdom to know the difference.
The problem is in the final caveat: How and where do I gain the wisdom to know the difference?
I think Ben Bergeron suggested an answer on Greg McKeown’s “Essentialism” podcast.
He suggested a person who complains, is nearly always complaining about something out of their control. Does this mean I shouldn’t complain? Not necessarily, after all complaining could be a signal to let me know something is out of my control. What I might do if I find myself complaining is ask myself how I might accept what is happening, (or how I might act to change it).