Dick Van Dyke, who recently reached 100, is the subject of a new documentary, "Dick Van Dyke: 100th Celebration", now screening in theaters nationwide.His eight-decade career spans Broadway's "Bye Bye Birdie", films like "Mary Poppins" and "Chitty Chitty Bang Bang", and the CBS series "The Dick Van Dyke Show", and he has won multiple Emmys, a Tony and a Grammy.In an ABC News interview with Chris Connelly he discussed health challenges and sobriety, credited his wife Arlene Silver for keeping him energized, said he still tries to dance despite reduced mobility, and recently published the book "100 Rules for Living to 100: An Optimist’s Guide to a Happy Life".