The word flabbergasted makes me discombobulated which in turn makes things all caddywaumpus which makes me want to sing supercalifragilisticexpealadocious. What was the question again?
The etymology of the word is thought to be just that, an arbitrary throwing together of flabby or flapper and aghast in the late 1700s.
I think you may be right .
My flabber has never been so gasted.