Do not make life hard to any  -  Ralph Waldo Emerson

A little thought will show you how much your own happiness depends on the way other people bear themselves toward you.  

The looks and tones at your breakfast-table, the conduct of your fellow-workers or employers, the faithful or unreliable people you deal with, what people say to you on the street, the letters you get, the friends or foes you meet - these things make up so much of the pleasure or misery of your day.

Turn the idea around, and remember that just that much are you adding to the pleasure or the misery of other people's days.  And this is the half of the matter which you can control.

Whether any particular day shall bring to you more of happiness or of suffering is largely beyond your power to determine. But whether each day of your life shall give happiness or suffering rests with yourself.