This past Christmas, I purchased as a gift for my mom a three-chamber crockpot.

I had never seen a crockpot with three chambers before, and figured it would make a nice addition to Mom's arsenal of cooking devices. I thought it would make preparing three separate dishes easier, as opposed to the one that you do with a traditional single-chamber crockpot.

I gave the crockpot to Mom on Christmas Day, and at first she was very enthusiastic about it. But when she read the instructions, she discovered there were certain limitations to the device that I was unaware of when I purchased it. Not being able to utilize it as we initially thought it could be used, Mom asked if she could exchange it, and I told her of course.

I told Mom I had purchased the crockpot at Kmart, and I would have been willing to bet a paycheck at the time that was exactly where I had bought it. But later Mom called and said when she had attempted return it for a refund at the Kmart in Williamsport where she lives, they said they had never carried the product.

Well! I was absolutely indignant at such a thought, and told Mom I had most certainly purchased the crockpot at Kmart. (I was thinking of the one in Wysox, if you're curious.) So she asked me if I could mail her the receipt, and I told her I would make an effort to find it, so we could settle the matter.

Fortunately, I was able to find the receipt rather easily the next day, but unfortunately, I made a rather disquieting discovery when I did. For the receipt indicated I had purchased it at Walmart, not Kmart.

Oh boy, was my face red. I had spent several years in the retail business, and had sometimes had to deal with customers who absolutely insisted that they had purchased a certain item at the store, and refused to budge an inch even when I informed them we had never carried said product. Now I knew what it was like to be on the other end of the stick.

Well I mailed Mom the receipt, called and apologized for the error. As I was putting things in order, I suddenly was able to follow the chain of events that made me think I had purchased the item at Kmart, when it was actually at Walmart. I had been at Kmart earlier in the day, and made a purchase. Then I went up to the Valley to get a prescription filled, and in the process, spotted the crockpot and purchased it for Mom. But when I gave it to her, and later, Kmart stuck in my mind and that's why I was so certain that's where I had made the purchase.

Okay, you're probably asking yourself right now, what's this got to do with the price of eggs? Good question.

Selective memory can be a funny thing - and sometimes can be a risky thing as well. There have been many times in which a person has "remembered" something, and is certain that what they are recalling is the absolute truth. Sadly, people have been convicted based on the evidence of such "memories" - in various cases including homicide, robbery, and other crimes - only to have other solid evidence surface later, proving the innocence of the accused. Many times, it's also been proved that those who gave the initial testimony weren't lying, they had instead been in serious error about what they had previously been absolutely certain of their facts as they remembered them.

This is why it is so important that we check and re-check information in circumstances such as criminal investigations - and yes, news stories - as well as numerous other things as well. Because a person can honestly be absolutely certain something has definitely occurred, and yet still be in error about the actual events.

C.J. Marshall is a writer and columnist for The Daily Review. He can be reached at cjmarshall@thedailyreview.com.