In 1991, 30 years after legendary comedian Johnny Carson started hosting 'The Tonight Show,' rumors began swirling that he was retiring. The news sparked a battle for Carson s seat between two comedians: Jay Leno and David Letterman. Ultimately, Leno won the coveted spot. In this 'Oprah's Next Chapter' clip, Letterman reveals why he'd thought that he was going to be the retiring Carson s heir apparent. 'Oprah's Next Chapter' airs Sundays on OWN.