Hmm...yea, "throw for a loop" means "it stunned me" but your question made me curious, and so I did a little research. Different sources had different explanations of the expression’s origin. Here are two explanations: "The ‘loop’ alludes to the comic-strip image of a person pushed hard enough to roll over in the shape of a loop." (from The American Heritage Dictionary of Idioms). “The 'loop' derives from the aeronautical term for the mid-air maneuver of an airplane. To knock someone for a loop is to hit that person hard enough to make them do a somersault. The feeling of dizziness and disorientation carried over into the more common figurative use.” (from Urdang’s Picturesque Expressions). You can read more about it here: http://www.wordwizard.com/phpbb3/viewtopic.php?f=7&t=20657

Lol... perhaps..... originally the term meant to "knock someone out" or render them unconscious.... It is like someone comes and hits you very hard and knocks you out.... how do you feel? Stunned, right? Or surprised.... that is the reason "threw me for a loop" means surprised me.

confused you