Grocery store induced amnesia

I have a problem with grocery store induced amnesia. I always, always manage to forget something - the all-important list is the worst, since I can't do anything without it. If I make the list on my own, I tend to forget some vital ingredient for a meal, say, the fish for a fish dish, or I don't remember to check how much of a crucial ingredient we have. Usually not enough is the correct answer. Today, I ran to the store to get a few things, and I managed not to get the first two things in my basket. Now, how can this happen, you ask? I have no idea. I know that I put them in my basket, and I thought I put them on the conveyor belt at the checkout counter, but when I was unloading the bag at home, they were nowhere to be found. At least they were also missing from the receipt - so I didn't get charged for something I didn't actually get home. Sigh.