You know less than you think you do - about what makes you healthy, what makes you rich, who you should date, where you should live. You know less than you think you do about how to raise your children, or, for that matter, whether you should have children in the first place. In his international bestseller, Everybody Lies, Seth Stephens-Davidowitz showed how big data is revolutionising the social sciences. In You Know Less Than You Think You Do, he shows how big data can help us find answers to some of the most important questions we face - and how these answers can radically improve our lives. From happiness to dating, money to sex, health to spirituality, this is self-help as we've never seen it before.