[It’s] the lens through which your brain views the world that shapes your reality. And if we can change the lens, not only can we change your happiness, we can change every single educational and business outcome at the same time.

Source: "The Happy Secret to Better Work." TEDxBloomington. May 2011. Conference Presentation. Additional Information: This quotes means that it's not our reality that shapes our perception of the world, but our perspective that shapes our reality. Thus, our external world is not predictive of our levels of happiness or success; the way our brain processes the world determines these things. In the TEDTalk that is the source of this quote, positive psychologist Shawn Achor explains this principle and how training your brain to become more positive can result in increased happiness and better educational and business outcomes. Watch the full TEDTalk here: Shawn Achor - The Happy Secret to Better Work