I started to make harder jokes before anyone else did. And the producers would get anxious. They'd say, 'That's a little bit hard-edged, isn't it?' And I'd say, 'Let's just try it and see how the audience reacts. If they don't like it, let's cut it out.' And the audience roared with laughter, so I learned you could do this harder humor and people loved it.
John Cleese