Am I the only person in the world who understands this expression?
I have fought and pleaded with people (my EX, especially!) to get the gist of this quaint, old-timey phrase and nobody seems to “get it” except me and members of my Appalachian family.
I’ll eventually post what I think it means, but what say you? Please reaffirm my sanity!
I’ve never even heard that expression before.
I’ve understood it as meaning the person in question didn’t just get his behaviors from nowhere; he got it from the way he was raised, the type of people he grew up around, etc.
Ditto. And I served for 23 years with people from all over the country.
It’s a new one to me. I don’t get its meaning.
Making it nearly unanimous, so far. I never heard that expression before and I don’t get it.
never heard it before.
Nope.
New to me.
Sorry, me neither. I’m assuming it means he didn’t pull that out of thin air?
I’m in the UK and have no idea what it means. 
Virginia, never heard it.
Texas, never heard it before.
Google says it’s an Irish saying. Anyone from Ireland who can confirm that?
Where do you hail from, and from who did you hear it?
Grew up in Valdosta GA as a kid. Parents from other parts of Georgia. Never heard the expression.
Makes even less sense to me than “May a moody baby doom a yam?” Midwest.
Never heard it, and can’t figure out what it might mean.
Go hang a salami. I’m a lasagna hog. 