I love this, from G. K. Chesterton:
How much happier you would be if you only knew that these people cared nothing about you!
How much larger your life would be if your self could become smaller in it; if you could really look at other men with common curiosity and pleasure; if you could see them walking as they are in their sunny selfishness and their virile indifference!
You would begin to be interested in them because they were not interested in you.
You would break out of this tiny and tawdry theater in which your own little plot is always being played, and you would find yourself under a freer sky, in a street full of splendid strangers.
—G. K. Chesterton, Orthodoxy (1908), chapter 2, “The Maniac”