Try "Epaminondas" I can't speak to the classical Greek origin which I think has nothing to do with the ancient Louisiana origin. But does this sounds like the fellow you're talking about:
Epaminondas used to go to see his Auntie 'most every day, and she nearly
always gave him something to take home to his Mammy.
One day she gave him a big piece of cake; nice, yellow, rich gold-cake.
Epaminondas took it in his fist and held it all crunched up tight, like
this, and came along home. By the time he got home there wasn't anything
left but a fistful of crumbs. His Mammy said,--
"What you got there, Epaminondas?"
"Cake, Mammy," said Epaminondas.
"Cake!" said his Mammy. "Epaminondas, you ain't got the sense you was
born with! That's no way to carry cake. The way to carry cake is to wrap
it all up nice in some leaves and put it in your hat, and put your hat
on your head, and come along home. You hear me, Epaminondas?"
"Yes, Mammy," said Epaminondas.
For more info check out the children's books: Epossumondas
Epaminondas is the epitome of the noodle-head genre and could easily be used in a sentence to describe someone who you told something to, but they failed to understand a word you said.