To be honest, realizing that we don't have to worry about things we can't change anyway is one of the most liberating experiences we can have.    

Can you do anything to relieve the congested downtown traffic during rush hour?  No?  Good, now there's no need to agonize over it.

Can you prevent other people from gossiping about things you think are none of their business?  No?  Scratch that one off the list, too.

Can you stop that stupid wall from being built along the Mexican border, or stop Congress from taking away the funding for it?  Follow-up question: can you get Mexico to pay for that idiotic wall?  No?  Terrific, you can now step away from the 24-hour news cycle about that issue.

Can you make someone not interested in you fall in love with you?  Can you prevent old age, sickness and death?  Can you make everyone you meet do whatever you want?  No?  Then why do you try?

It goes on and on.  We encounter countless situations every day, some minor, some not so much, that we can't control.

The Stoics tell us that all we need to attend to is that which we can control - our own reactions to all those external impediments.