“But—let me tell you my cat joke. It's very short and simple. A hostess is giving a dinner party and she's got a lovely five-pound T-bone steak sitting on the sideboard in the kitchen waiting to be cooked while she chats with the guests in the living room—has a few drinks and whatnot. But then she excuses herself to go into the kitchen to cook the steak—and it's gone. And there's the family cat, in the corner, sedately washing it's face."

"The cat got the steak," Barney said.

"Did it? The guests are called in; they argue about it. The steak is gone, all five pounds of it; there sits the cat, looking well-fed and cheerful. "Weigh the cat," someone says. They've had a few drinks; it looks like a good idea. So they go into the bathroom and weigh the cat on the scales. It reads exactly five pounds. They all perceive this reading and a guest says, "okay, that's it. There's the steak." They're satisfied that they know what happened, now; they've got empirical proof. Then a qualm comes to one of them and he says, puzzled, "But where's the cat?”
― PKD