He comforted Steven Spielberg during the filming of Schindler’s List.
Schindler’s List was a very emotional and difficult movie for Steven Spielberg to film. To cheer him up, Robin Williams would call Spielberg once a week and make him laugh. “Robin knew what I was going through, and once a week, Robin would call me on schedule and he would do 15 minutes of stand-up on the phone. I would laugh hysterically, because I had to release so much,” Spielberg said.
yea and look where that idea is today