From Mitch Hedberg's comedy bit about the vending machine with an HH button. He presses H twice instead of the HH button and gets the wrong snack.

Generally, an exclamation of extreme frustration.

Specifically, an exclamation of extreme frustration when you made the wrong choice based on insufficient or faulty information, usually said of something trivial like getting the wrong snack out of a vending machine.
"I was gonna get a candy bar; the button I was supposed to push was HH, so I went to the side, I found the H button, I pushed it twice. Fuckin'...potato chips came out man, 'cause they had a HH button, for Christ's sakes! You need to let me know. I'm not familiar with the concept of HH. I did not learn my AA-BB-CC's. God god dammit dammit." - Mitch Hedberg

Ah, man! I ordered the deluxe platter and it turns out it's a fuckin' veggie burger and a soy-based milkshake. God God Dammit Dammit!

She told me over the internet that she was a virgin, and I was all excited, but it turns out she's also really ugly. God God Dammit Dammit!
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