I believe Claudia Cardinale once said that, on set, while Luchino Visconti demanded that everyone quieted down so he could think, Fellini used the hustle and bustle of the ambient to help his thinking process.
He was the best type of madman there could ever be: the one that's madly in love with life and made sure everyone knew that through his art. Don't you wish you could've hung out with him?