Have you ever screwed up grocery shopping self-check so badly you messed up the bill for a total stranger?

Let me back up a bit. It's the holiday confection season, and my wife wanted to make some caramels and spiced nuts for office-party gift bags. I was dispatched to the store to pick up a few things.

Condensed milk: easy enough. Two cans with Elsie on the label. Cayenne pepper for the nuts. Oh, need some cola. Any sales? Yes: there's a tag lying right on the brand I want. Three for $14. Then it's off to the self-checkout. Usual drill: Enter my rewards number so I can be rewarded. Push the button that says "I'm using my own bag," after which I am instructed to place the bag on the table.

I do so, and receive the message: UNEXPECTED ITEM IN BAGGING AREA!

It's the bag, machine! The one I just told you about! Houseflies have longer memories than this stupid thing. Anyway. Beep the cola. Hello, it's $8. Sigh. Call over the person who stands at a small podium like a bored pastor without a sermon, waiting for someone to sin.

"This came up as 8 bucks, but the sign on the package said three for $14." He nods, certain I am in error, and consults a pamphlet of current coupons.

The soda was not, in fact, three for $14. It might have been that yesterday. It might be that tomorrow. But not now. In the ever-shifting world of soda prices, I had chosen the folly of full price.

At this point my phone rings, and it's the wife, a bit concerned: "Are you still at the store? I need light corn syrup."

No, I'm still here, suffering from the unspoken judgment of Father Selfchek, who has frankly had his fill of people who cannot read the simplest of signs.

Back to the baking department. The corn syrup came in two sizes: 16 ounces and a full quart. Both were on sale. The 16-ounce version was $2.49. The quart was $5.49.

Now, I was an English major who avoided the hard sciences like a vampire turns away from holy water, but even the vampire knows the stuff is just H20, and even I know this price is askew. Two 16-ounce containers for $4.98 is less than one quart for $5.49. Well, I'd be a fool not to buy two smaller units! Hah! Gettin' one over on the Man!

A fellow was reaching for the quart bottle, and I, wanting to spread the good news to my fellow corn-syrup procurers, pointed out the price difference. He took two of the smaller units. "Wife making caramels?" I asked.

"No, I am," he said, making it two people who had expressed contempt to me since I'd entered the store, Father Selfchek and the Homemade Caramel King here.

Back to the checkout. Beep, beep, beep ... hey. The syrup's coming up at $3.49. I have no choice but to wave to Father Selfchek. I explain the situation, and admit that yes, I was wrong about the cola, but I'm positive I'm right about this. He starts to consult the coupons. Meanwhile, Caramel King walks past, and I stop him. "Check your receipt!" I advise.

He checks. It's $3.49. He shrugs. Well, time is money, too, and there are caramels to be made, so he doesn't stop to adjust the bill.

Meanwhile, Father Selfchek can find no proof of my claim. I say I'll go take a picture of the price tag, which he says he will accept as evidence.

I walk back, muttering under my breath. To my horror, the sign for $2.49 refers to the store brand syrup, which is waaaay in the back of the top shelf. It could not be seen if you are my height, which to be fair is the same as Napoleon's, and he accomplished a lot. Although Josephine probably held her breath every time he went to the grocery store, or to Russia.

Then I did something for which I am a bit ashamed, and this is my confession: I pushed the house brand over a bit so it looked as if the lower price might apply to the name brand, if one was charitably inclined. I took a picture to explain my "mistake." I paid for two house-brand units, bought those, and left in a hot flush of shame, wondering how I could pay back Mr. Caramel King.

Bless me, Father, for I have scanned.