I was bagging my groceries when the checker handed me my receipt and said, “Happy Yesterday.” Unsure of the correct response, I just smiled at him and nodded.A few moments later I realized he had said, “Happy rest-of-your-day.” But that brief exchange put my mind on an interesting track: can we choose to have a happy yesterday?Strangely, we can. According to a number of studies published since 2012, we don’t really remember the events in our lives. We remember only our last memory of those events. Events in our memories alter and morph with each retrieval until, finally, we are “remembering” things that never really happened.The first of these studies was conducted at Northwestern University and published in the Journal of Neuroscience.On September 19, 2012, journalist Marla Paul wrote,“Remember the telephone game where people take turns whispering a message into the ear of the next person in line? By the time the last person speaks it out loud, the message has radically changed. It’s been altered with each retelling.”“Turns out your memory is a lot like the telephone game, according to a new Northwestern Medicine study. Every time you remember an event from the past, your brain networks change in ways that can alter the later recall of the event. Thus, the next time you remember it, you recall not the original event but what you remembered the previous time.”“‘A memory is not simply an image produced by time-traveling back to the original event,'” says Donna Bridge, a postdoctoral fellow at Northwestern University Feinberg School of Medicine and lead author of the paper on the study recently published in the Journal of Neuroscience. ‘Your memory of an event can grow less precise even to the point of being totally false with each retrieval.’”In a subsequent article in Psychology Today, we read,“Not only are our memories faulty, our memories change each time they are recalled. What we recall is only a facsimile of things gone by. Memories are malleable constructs that are reconstructed with each recall. What we remember changes each time we recall the event. The slightly changed memory is now embedded as ‘real,’ only to be reconstructed with the next recall. Memory isn’t like a file in our brain, but more like a story that is edited every time we tell it. We attach emotional details with each re-telling. Not only do we alter the story, we alter our feelings about it.”We unconsciously choose to alter these emotional details and feelings for better, or for worse. To make ourselves happier, or more miserable.I vote for remembering happiness. “Have a happy yesterday.”“But Roy,” I can hear you say, “you’re saying that we should lie to ourselves.”No, I’m simply saying that you’re already lying to yourself when you believe that you recall past events accurately.The simple, scientific truth is that you colorize events each time you recall them. I’m merely suggesting that you consider the colors you are choosing.Will they be dark, sad, angry colors? Or will they be warm and happy ones?Roy H. Williams