He stands still while the front of the house comes down on him, and the open attic window passes over him, and he doesn't move a muscle, doesn't even look up — this is Steamboat Bill, Jr., 1928, two tons of facade and not much room either side. I've run that reel more times than I can count and the house still does the same thing: a small collective inhale, about four seconds, then nothing, because nobody wants to be the one who breathes out first.

Cut to Piqua, Kansas, 1895, and a vaudeville family with a toddler in it. By three he's in the act, and the act is his father picking him up and throwing him about the stage — he got billed as the Human Mop. He worked out early that the straight face sold it. Smile, and the audience relaxes and stops laughing. Stay blank, and they do the worrying for you.

Then the long flat stretch nobody puts on the posters. He lost the little studio and the control that came with it, and through the thirties he was mostly writing gags for other people's pictures on a modest salary, the sort of credit that doesn't go on a card. Took until 1959 for the Academy to hand him an honorary one. He was still falling over for cameras right up to 1966, and falling over properly, with the knees.