"Pivot" is often viewed as a dirty word in the startup world, with the assumption being that the founders failed in some way. But sometimes failing — or at least acknowledging you're on the wrong course — is the best path toward success.
Are you working on a startup? If so, I hate to break it to you, but there's a good chance it will fail. In fact, recent research shows that 75% of startups fail (based on a study of 2,000 startups that received VC funding from 2004 to 2010).