Twenty-five years ago this week, the action movie Die Hard opened and Bruce Willis uttered that famous line.

But where does the yippee-ki-yay part come from?

The yip part of yippee is old. It originated in the 15th century and meant “to cheep, as a young bird,” according to the Oxford English Dictionary (OED). The more well-known meaning, to emit a high-pitched bark, came about around 1907, as per the OED, and gained the figurative meaning “to shout; to complain…”

Now how about the whole phrase, yippee-ki-yay? It seems to be a play on “yippie yi yo kayah,” a refrain from a 1930s Bing Crosby song, “I’m An Old Cowhand.”

Do cowboys really say this? We’re guessing probably not, unless of course they’re single-handedly (and shoelessly) defeating a gang of bank robbers on Christmas Eve.

Have to realize, folks, just how popular Bruce Willis is in working class America. I know a few cowhands in my neck of the prairie and I’d bet they’re not alone in repeating BW’s badass bravado. In fact, I have no doubt there are beaucoup more non-cowboys than cowboys ready to play at being a Willis-style hard man. With or without a proper H&K MP5 Machine Gun.