I’ve definitely said it. You’ve probably said it. When referring to a large amount of stuff, you’ve called it a “butt load.”
I had always assumed the expression was hyperbole and a slightly more polite way to say you’ve got a lot of shit. Well, I was wrong. A “butt” is an actual unit of measurement equivalent to two hogsheads or 126 gallons. That’s still a lot of shit. Just, hopefully, not literal shit.
When clicking the measurement link, see also, “megadeath.” It’s not just a metal band.