At lunch with my husband and adult daughter, I launched into a story about an incident in my youth. It was Eastertime. In my kindergarten classroom, I sat at table painting an eggshell with its yolk blown out. A boy whose name I still recall threw a ball from behind me, knocking a paint bottle into my lap. Over our meal, I conjured up every detail from that time.

When my husband asked about the paint color, I first answered purple. But 1960s schoolrooms had amassed bottles of mostly primary paints. Despite not knowing the color, the stinging odor of acrylic paint and the chaotic classroom stayed with me all these years. How was that so?

How are memories made, and how do they help us cope during difficult times?

The Science of Memory

I am the daughter of a mother who experienced dementia. Whenever I misplace my iPhone, I fear my memory is slipping. Author Lisa Genova, author of Still Alice and renowned neuroscientist, says not to worry. But if I forget how to use my phone, it’s time to consider help.

In Ms. Genova’s latest book, Remember, she breaks down the four-step process of memory-making. First, encoding occurs when an event is captured through the senses and translated into what she calls a “neurological language.” Next, in consolidation, those random bits of information are woven together in single pattern of neural connection. Storage is maintained through structural changes in those neurons. Finally, during retrieval, something occurs to activate that memory—a discussion in a boisterous café, the pungent smell of paint, the cool feel of an eggshell—and now, that memory is recognized and revisited. All these events occur in the brain’s hippocampus.

In our brains, the hippocampus is the memory weaver, linking various pieces of information into some sort of meaning for us. If the hippocampus becomes damaged, as for those diagnosed with Alzheimer’s, one’s ability to create new memories is impaired, and the process of forgetting begins. This manufacturing of memories is also time dependent. If someone fell off a ladder and experienced traumatic injuries, they might remember the frightening plummet but not the painful landing. The completed memory might be lost.

This all makes sense until one day, we depart from our origination, drive across a bridge, and find ourselves on the other side with no recollection of how we got there. How did this happen? As the author states, “Your memory isn’t a video camera. You can only remember what you pay attention to.” I didn’t recall the paint color because time was interrupted and because other factors consumed my attention, such as needing a change of clothes.

A Rosy Outlook for Nostalgia

Why did I bring up the kindergarten story during that lunch? Our lunch guests also included a teacher. I felt nostalgic in that moment for when our kids went to school, for when I did. What did nostalgia have to do with memory? Everything. 

In the 1600s, nostalgia was considered a neurological condition that resulted in depression and anxiety. The first study of nostalgia was formulated around the German army. Their anxiety was thought to be caused by the ringing of nearby Swiss cow bells or changes in atmospheric pressure.  Since that time, scientists have discovered nostalgia is a longing for the past. And this longing can make us feel better in the present. Felipe De Brigard, a professor of psychology and neuroscience at Duke University, says, “It’s a mental vacation without leaving home,” especially when one is alone or in a situation with negative overtones.

The popularity of memoir contributes greatly to this conclusion. The memoir writer pens a book about a pivotal time her life. In doing so, she re-experiences the past to feel better about or understand choices that were made. As noted by actor Rob Lowe, interviewed in the Happiness Lab podcast, “I need that clarity of what would I have done differently.”

There are other ways to experience nostalgia. Lee Thompson, a professor at the Kellogg School of Management and world-champion cyclist, performed a study that concluded emotions felt prior to and after an event are more positive than those while we are in the event. In her research, cyclists answered a series of questions about their present feelings as they pertained to an upcoming trip. Beforehand, cyclists answered positively about the event on 27 out of 28 questions. This she called rosy prospection. Following the event, that number was 26/28, creating rosy retrospection. But during the trip, when water was scarce or a rider suffered from sunburn, cyclists rated the event 20 out of 28.

Our minds like a joyful ending or at least a tidy one. This is how we build stories or make sense of our world. To use our memories productively, we must maintain awareness, store them appropriately, and recall them with transparency. The kindergarten story made me think of that young boy, who I remembered as troubled, because of one incident. He never set out to harm me. I’d like to find him and set my memory straight.