"It's almost like a drug, because you get this kind of immediate adrenaline rush, especially if you're finding stuff," Robin said in 2006.
Dr. Phil McGraw explained the appeal that making people laugh has for comedians, saying, "As long as [the audience] is laughing and talking, they're not focusing on them, so it doesn't really get healed."
"I didn't want anyone to know about me," Robin said in 1986. "I didn't want people to know the quiet side or any other side, because of fear of what they would do with it."
Laugh Factory founder Jamie Masada, who has seen many comic legends come and go, told ET's Nancy O'Dell that Robin kept up a happy façade until the end.