In Reply to: You crack me up posted by A Harbone on June 09, 2010 at 17:28:
: What is the origin of the phrase "you crack me up"?
My guess. You make me laugh so hard that I lose all of my faculties. Have a little breakdown. As in the second meaning here:
To "crack up" can either mean "to praise highly" (As in, "He's not what he's cracked up to be.") or (the more common usage in the U.S., at least) "to break down in health or mind." From "Brewer's Dictionary of Phrase and Fable" revised by Adrian Room (HarperCollinsPublishers, New York, 1999, Sixteenth Edition).