Capt Mainwaring: "Now pay attention, men. I've come up with this idea for learning to drive a miniature tank before High Command give us full-size ones, and, er, Private Walker has managed to get these built for us. I want you each to get in one of them, and I'll judge your driving skills."
Sgt Wilson: "Aren't they a bit small, Sir?"
Capt Mainwaring: "Very good, Wilson. I was wondering who'd be the first to notice that."