It's been stuck in my head for a while now and I finally got around to using this "internet thingy" to find out what it means.
I'm kind of a word nut in that I really like knowing what words and phrases mean. I mean, really mean. I know what Thing here means when he said "Oh, fer the love of Mike." He's swearing an oath. But since swearing is bad, you've got to turn the phrase.
Like when people say, "Oh for Pete's sake." They are avoiding saying the word "God". I imagined that was the reason for the Mike substitution. But who the hell is Mike?
Well, I'm gonna tell ya!
I found out that this phrase is actually between 600 and 800 years old. It was a soldier's oath. And since swearing is bad, saying the word "God" in your swear is even worse. It's one of the Big 10 ya know. So rather than risk an eternity in Hell, they started swearing to Mike. As in St. Michael, the patron saint of warriors and the Archangel that sent Satan to the hot seat.
Linguists and etymologists have a term for this. It's called a minced oath. Like when you step on a Lego in the middle of the night and feel like screaming, "Jesus Christ!" you instead bite your tongue and squeak out, "Cheese and rice!" See? You get to turn an eternity of damnation into a delightful side dish.
I learned all this by visiting Bill Casselman's website where he explained this in well written detail. I absolutely love that there are people in this world that study this stuff for my benefit. I'm not sure how long he studied in order to know this, but it only took me three minutes thanks to him.