UFO Witness: "Look, there's a UFO up there!"
Skeptic: "Nah, those don't exist!"
UFO Witness: "No! Look! It's a saucer! And it's coming closer"
Skeptic: "No way! That's a bird wanting to be fed, or a deflating balloon, of course!"
UFO Witness: "My god, it's right above you, zig-zagging back and forth, man!"
Skeptic: "Nope! It's a big hat, or it might be a hubcap someone has thrown at us, and that's parallax."
UFO Witness: "Good Lord! It's right on your head!!"
Skeptic: "No it's not! It's just an illusion; the hat is on a distant hill."
UFO Witness: "No! It's on your head! Right on your head!!"
Skeptic: "Click.. Click.Click…. Cliiiick…"