The greatest discovery of all time is that a person can change his future by merely changing his attitude Oprah Winfrey dhavalvadi 4 years ago The greatest discovery of all time is that a person can change his future by merely changing his attitude Oprah Winfrey 1 The greatest discovery of all time is that a person can change his future by merely changing his attitude Oprah Winfrey The greatest discovery of all time is that a person can change his future by merely changing his attitude Oprah Winfrey