In 1971, Mel Stuart offered Wilder the lead role in his film adaptation of Roald Dahl's Charlie and the Chocolate Factory. Wilder was initially hesitant, but finally accepted the role under one condition:
When I make my first enterance, I'd like to come out of the door carrying a cane and then walk toward the crowd with a limp. After the crowd sees Willy Wonka is a cripple, they all whisper to themselves and then become deathly quiet. As I walk toward them, my cane sinks into one of the cobblestones I'm walking on and stands straight up, by itself... but I keep on walking, until I realise that I no longer have my cane. I start to fall forward, and just beore I hit the ground, I do a beautiful forward somersault and bounce back up to great applause.
When Stuart asked why, Wilder replied, "because from that time on, no one will know if I'm lying or telling the truth.
(Source: wikipedia)