British-born restaurateur Keith McNally opened such popular New York City institutions as the Odeon, Balthazar and Pastis. But a 2016 stroke, which caused immobility and affected his speech, led to a suicide attempt two years later. In this web exclusive, he talks with correspondent Mo Rocca about writing his memoir, “I Regret Almost Everything”; how the stroke drew him to Instagram; how he learned restaurant lighting through an early job in theater on “The Rocky Horror Show”; and giving second chances.