Why do we remember summer holidays better than the rest of the year?

Evening ice cream and a walk by the sea, picnics in the cool air, dances and town festivals… If we were to take a catalogue of our best memories, surely the vast majority would be of our summers and holidays. Few, surely, would be about the long winter afternoons or our daily work. Why does this happen? As is usual in these matters, neuroscience has a lot to do with it.

“The brain is not a passive recorder of our lives, but is constantly evaluating and filtering the information it receives to store it according to its usefulness or because it defines us,” explains biomedical researcher Marta Trillo, author of the book "How Your Brain Decides" (Pinolia). From here, the main reason why we tend to remember summer more than other times of the year is novelty.

During the rest of the year, Trillo explains, most of our days are based on living in automatic mode: we wake up, go to work, and do a very similar routine every day. For this reason, it is very likely that we do not remember the path we take on any given morning to the workplace. "This memory is stored in the memory in a general way, as a schematic representation," says the researcher. In this way, all repetitions are grouped into the same concept, as it is the same event with small variations between them.

All this changes in the summer and during the holidays, times when we tend to make more plans that deviate from the usual. Meetings with friends and family or returning to the village of a lifetime are things that the brain usually associates with positive childhood memories. If we add novelty to this, it becomes a perfect cocktail to generate what Trillo calls "episodic memory": those memories of our lives that we can consciously recall.

"The hippocampus is one of the areas of the brain responsible for storing new memories. And it responds with more intensity if the event is stimulating, as usually happens with the plans we make during the summer," the author clarifies. Furthermore, this fact produces another effect: that when looking back, summer seems to be a longer period of time compared to the rest of the year. "This is because these memories are stored individually," she emphasizes.

First experiences

On the other hand, all the plans made during holidays tend to be planned months in advance. This fact causes other areas of the brain to become involved which, together with emotion, "cause a cascade of molecules like dopamine, which favors it being fixed in the hippocampus more sharply," says Trillo. Furthermore, the reward circuit is also activated in this whole process: the ventral tegmental area of the brain releases dopamine in anticipation. In other words, emotions are key for a memory to leave a good imprint on our minds.

Experts agree that we tend to remember summers from when we were young better. Firstly, this is due to the well-known "reminiscence bump." Adults remember experiences lived between the ages of ten and thirty more intensely because they are usually loaded with novelty, emotion, and many firsts. Summers of youth, over time, are not only remembered: they are reinterpreted as if they were even more intense, freer, and happier than they perhaps were. At this point, moreover, we are building our identity, that "personal brand" with which we will later explain the world to ourselves.

Along the same lines, nostalgia is not just memory: it is also reconstruction. According to various studies, the brain does not recover the past as it was, but as it reinterprets it from the present. That is, we tend to "edit" memories so that they fit the story we tell ourselves about ourselves.

This has an evolutionary and emotional explanation: remembering things better than they were helps us maintain an internal narrative and a certain emotional well-being with ourselves. And summers, with their concentration of emotions, novelties, and social relationships, are the perfect material for this kind of reworking.

But there is another key factor: neuroplasticity. During childhood and adolescence, the brain is much more plastic, meaning it has a great capacity to reorganize itself based on experiences. This causes experiences to be "etched" more deeply, not so much as an exact file, but as deep connections between emotions, smells, places, and sensations. That is why, years later, something as simple as the smell of sunscreen or the sound of crickets can trigger a complete memory: the beach, the light, the salty skin, and that sensation of infinite time.

Childhood memories

There is another great phenomenon that also helps us understand to what extent the brain is selective: childhood amnesia. That is, the inability of most adults to remember events from their first three or four years of life.

One of the landmark studies is by Patricia Bauer and Marina Larkina, published in 2014. The researchers followed a group of children from the age of three. At that stage, the children were able to explain recent experiences in detail. Years later, the same participants were interviewed again to check what they remembered.

The results showed that between the ages of five and seven, they still retained more than sixty percent of their memories; but from the age of eight and nine, this figure dropped below forty percent. That is, the memories are there, but over time they become increasingly less accessible.

It is believed that it is not that there is no memory during childhood, but rather that its system is still under construction. The brain has not yet finished developing the mechanisms that allow transforming specific experiences into stable autobiographical memories. In other words, memories are generated but not stored with the same solidity as in adulthood.

A second factor would be that during early childhood, what neuroscientists call the "autobiographical self," the ability to place an experience within a personal narrative, has not yet been fully consolidated. Without this structure, the memory is not anchored as "one's own" in a stable way. And the third is language. Before mastering it, many experiences are purely sensory and emotional. But it turns out that everything that cannot be easily verbalized later has more difficulty in becoming a long-term memory.

Circadian rhythm

All in all, the very season of the year also modulates the functioning of the brain. According to Trillo, it has been observed how the neural networks involved in attention, memory, and the reward system show seasonal variations. The brain, in a way, does not function exactly the same throughout the year.

One of the main keys is sunlight. Some research has shown that serotonin increases with exposure to natural light. This neurotransmitter is linked to the feeling of well-being, motivation, and emotional stability, which helps explain why we often experience the summer months with more energy.

The biological clock also plays an important role. The brain, through the suprachiasmatic nucleus, regulates circadian rhythms and coordinates hormones such as cortisol or melatonin. Changes in schedules, longer nights, or reduced sleep can alter this system and affect both memory and mood.

In the end, we not only experience summer differently: we also encode it differently in the brain. Perhaps that is why, when we remember it months or years later, we do not retrieve it as a simple set of days, but as a set of sensations: light, time, emotional intensity, and a certain idea of freedom. And so, the brain does what it always does with summers: it does not archive them, it transforms them.