A wise rule to live by

I am traveling for work this week and, because the weather is bad and I am slightly afraid of flying, I am feeling tense. Which translates to grouchy.  So imagine my surprise (chagrin) when I found that my gate area is being accosted by a lady troubadour, playing her guitar and singing in that clear, earnest lady tone that is so popular among coffee shops and cereal bar commercials.  So, being the grumpy wart that I am, I tossed a quick text off to my likeminded, sourpuss spirits - my mother and sisters, describing the live music situation in terminal A. This was my sister's prompt response:

"In general, people should not assume that the world will find them delightful."

Which, ironically, delighted me more than anything I've read in a long time.