A brunette, a redhead, and a blonde are on a carpet that makes you disappear if you lie.
Brunette: "I think I'm the most popular kid in school." *WHOOSH!* she disappears.
Redhead: "I think I'm the prettiest kid in the school." *WHOOSH!* she disappears.
Blonde: "I think . . . " *WHOOSH!* she disappears.