What's your best "what an airhead" story?

When I saw the following tweet: "Not all Islam are ISIS, but trust me, all ISIS are Islam." Didn't know whether to laugh at the logic or the verbiage.

This kid I know doesn't think anything significant isn't in the country he lives in (australia). He said the other day "Oh so mt Everest is the tallest mountain in Australia right?" Total dumbass.