"Interviews with Cosby are unlike anyone I've ever interviewed because he doesn't really answer your questions, he just starts telling stories," said Mark Whitaker, author of Cosby: His Life and Times, out tomorrow.
Cosby gave ET the secret to good parenting in 1986.
"Give them wisdom, give them love, support them spiritually, and then send them off to college, and then the wheels come off," said Cosby.
Sadly, tragedy struck the Cosby family in 1997 when son Ennis was killed at the age of 27 during an attempted robbery in Los Angeles.
"He carries reminders of Ennis wherever he goes," said Whitaker. "If you see Cosby perform now, every single concert he gives he's either wearing or has on the seat where he performs sitting down a sweatshirt that says 'Hello Friend,' which was Ennis' signature greeting."