Why You Have to Forget Something To Remember Something Else
Do you frequently forget where you left your keys but can recall with crystal clarity the days leading up to and after your wedding 40 years ago? You’re in good company. That is why when people learn that Charan Ranganath, PhD, is a memory researcher, they usually ask him some variation of the same question—“Why do I feel like I’m always forgetting?”
His response: You are always forgetting…and that’s a good thing. Instead of asking, “Why do I forget?”…try asking, “Why do I remember?” The ability to remember recent events (episodic memory) declines with age, while personal insight and knowledge of the world (semantic memory) stays strong. The aging brain is literally designed to prioritize the retention of old information over the formation of new memories. This biological adaptation has shaped elders’ roles in families and communities, allowing them to pass along cultural knowledge and general life experience to younger generations.
Dr. Ranganath explains that the human brain is not designed to remember everything. If we did, our heads would be like packed-to-the-gills automobiles, groaning under the excess weight. Just as you couldn’t drive that car very fast—or safely—because your windshield and rear-view mirror would be obscured, you don’t want a brain that hauls around everything you’ve ever learned or experienced. You want your brain to be clean, organized and agile so that you can pull out specific memories at a moment’s notice.
In 2012, research at University of California published in International Journal of Communication estimated that the average person processed 100,000 words and 34 gigabytes of information each day—that’s enough to fill seven DVDs or one-fifth of a computer’s hard drive. That number has surged in the past 12 years as screen use has more than doubled. With so much data being thrown at our brains, it would be impossible to commit even a tiny fraction of all that to memory.
The Truth About Memories
It may seem like memories live in the past, but think of them instead as a pool of resources to help you plan your future. The ability to travel back in time helps you predict how you might feel going forward…
Examples: Let’s say you recently retired and are deciding how to spend your next few years. A friend suggests you travel…so you start thinking of all the trips you’ve taken throughout your life, and memories begin to bubble up—not of every vacation you’ve ever taken but of the key ones that you enjoyed…or that flopped. These memories help you answer the general question, Do I enjoy traveling or not? Perhaps you loved the family trips to Florida and a work conference in Hawaii but disliked visiting relatives in frigid Minnesota. Those memories help you narrow future travel plans to warmer climates. The same goes for more mundane events, such as a colonoscopy. You recall that it took only an hour for the bowel prep to kick in, so you are reminded to stay close to the bathroom this time.
Here are a few other memory-centric takeaways that will help reframe how you view the art of recollection…
Brain byte #1: Leave a trail of memory breadcrumbs. The brain loves novelty, so it tends to tune out during mundane tasks or routine activities such as putting down your keys or cell phone when you enter the house. The key is connecting easy-to-forget but essential things, such as where you’ve left your phone, with distinct environmental elements that feed your memory’s appetite for newness. As you set your phone down and prepare to unload the groceries, take a micro-moment to focus on a nearby detail or two—the color of the countertop where you’re leaving the phone or the nearby vase of flowers.
Or if you want to remember to take out the garbage, visualize some of the various cues you’ll have access to—the back door of your house that leads to the garage…or the bright blue recycling bin on the side of the house. These details act like purple sticky notes in a sea of yellow notes, so they will be easier to recall when needed. This is why some large parking garages name the different levels after singers or colors…it’s easier to remember you parked on the “Barbra Streisand” level than “Floor 2.”
Brain byte #2: Sharing memories with others helps us learn about ourselves. Example: Years ago, I had a near-death experience while stand-up paddleboarding with a fellow memory researcher. My board hit something underwater, and I capsized and became caught in a dangerously fast current. My friend and I spent more than five hours navigating frigid water around massive logs before finding our way back to our camp.
At first, I didn’t want to talk about the incident, but as I began sharing our story, I noticed my tone shift as people responded with emotions ranging from shock to empathy to admiration. Their feedback helped me reconstruct my memory with a different perspective, and I gradually began to see the experience as less about my panic at the time and more about my personal perseverance. Soon, when my colleague and I were telling the story together, we even started to play off each other, adding humorous elements, and our saga morphed from frightening to entertaining.
When we remember, we’re not replaying the past so much as using our current beliefs and perspectives to assemble bits of previous information and create a story out of it. Then, when we share those memories with friends, family, colleagues, even strangers at a cocktail party, their feedback helps reshape our memories. This is called memory updating, and it allows us to transform memories of negative experiences into positive ones.
Memory updating also is the special sauce in psychotherapy. You relay your experiences to a professional who isn’t burdened by your point of view. In turn, he/she questions your assumptions about your story and suggests alternate versions that help you challenge your thought processes and create new paths for moving forward.
Brain byte #3: Stop media multitasking. You sit down at your computer to check your e-mail. After just a few minutes, you remember that you need to book a dentist appointment, so you call your dentist and mindlessly scroll through Facebook while waiting for someone to answer. After booking the appointment, your phone pings that you have a text from a friend. You answer it, then return to checking e-mail.
This flipping between media streams—known as media multitasking—is a modern-day memory mischief maker. Toggling between your phone, e-mail and news websites overloads the brain’s prefrontal cortex (PFC), the region in charge of focus and executive functioning, so you end up forgetting much of what you see. That may not matter if you’re trying to describe a silly meme that a friend texted you, but it does matter if you forget to pay the tax bill your accountant mentioned in the e-mail you read while opening the meme. (On a more serious note, media multitasking’s negative toll on attention is why talking on the phone while driving is so dangerous.)
Media multitasking is linked with thinning of the PFC…and constantly shifting attention from one task to the next is stressful for the brain, and that stress prompts the release of hormones that interfere with short-term memory. If you’ve ever found yourself talking on the phone when the doorbell rings…checking to see who’s at the door…then find yourself asking, “Now, what were we talking about?” when returning to the phone call, you know what I mean.
Better: Try monotasking, blocking out time to focus on one task at a time. That may mean checking e-mail only twice a day for 10 minutes each, putting away your phone, turning off any alerts on your smartwatch and not checking other websites during those times. Then you can schedule separate chunks of time for computer work and other times for mindless surfing.
