Yogananda Paramahamsa has a beautiful suggestion for thawing the arctic state of our feelings; it is for all of us to become smile millionaires. This is the kind of millionaire that everyone can be, because everywhere we go we can always smile. Whenever you find someone seated alone, not knowing what to do, feeling utterly desolate, just smile at him. Almost everyone will thaw immediately and smile back. When you have been smiling at people in the park, at meter-maids passing by, at the mailman, and at schoolchildren, one day when you go to the mirror you will find smiling has become a habit. Your mouth has forgotten to droop at the corners; you try your best to scowl but you have lost the ability. Depression, unsociability, and lack of good will are beginning to get erased from your consciousness.
— Eknath Easwaran, The Bhagavad Gita for Daily Living: Volume 1