"It's a common belief that positive thinking leads to a happier healthier life. As children, we are told to smile, be cheerful and put on a happy face. As adults, we are told to look on the bright side, to make lemonade, and see glasses as half full. Sometimes reality can get in the way of our ability to act the happy part though. Your hopes can fail, boyfriends can cheat, friends can disappoint. It's in these moments, when you just want to get real, drop the act, and be your true scared, unhappy self.
Ask most people what they want out of life and the answer is simple: to be happy. Maybe it's this expectation though of wanting to be happy that just keeps us from ever getting there. Maybe the more we try and will ourselves to these states of bliss, the more confused we get - to the point where we don't recognize ourselves. Instead we just keep smiling: trying to be the happy people we wish we were. Until eventually it hits us: it's been there all along. Not in our dreams or our hopes - but in the known: they're comfortable, they're familiar."
... Grey's Anatomy, Season 6: Shiny Happy People