“To do any thing, to dig a hole in the ground, to plant a cabbage, to hit a mark, to move a shuttle, to work a pattern, –in a word, to attempt to produce any effect, and to succeed, has something in it that gratifies the love of power, and carries off the restless activity of the mind of man. Indolence is a delightful but distressing state: we must be doing something to be happy.”
–William Hazlitt, “On the Pleasure of Painting”
In my First Splendid Truth, in which I lay out my own formula for how to be happy (!), I describe this as “the atmosphere of growth.” It took me a long time to grasp how this element fits into happiness, but once I understood it, I realized how crucial it is.