When I walked into my childhood home for the first time in years, the scent of freshly baked bread hit me before anything else. Instantly, I was back in the kitchen with my mother, kneading dough at the counter as sunlight streamed through the windows. The feeling was so vivid that I could almost hear her humming softly as she worked. I didn’t expect a smell to unlock memories so clearly, but there it was—more powerful than any photo or sound.

Whereas, certain unfamiliar smells can feel unsettling. Moving to a new apartment once, the smell of the cleaning products in the hallway lingered for weeks. It wasn’t unpleasant, but it felt wrong—like it belonged somewhere else. No amount of rearranging furniture could make the place feel right until that scent faded, and the space began to carry traces of my own daily life.

Relatable scenarios are everywhere, for example, the smell of a particular perfume might instantly remind you of a dear friend, even if you haven’t thought about that person in years. A whiff of a familiar perfume can transport you to a moment shared with someone you love. The smell of rain on dry soil might take you back to a childhood summer, or a certain spice that reminds you of a family meal from years ago? 

Smell, it seems, is not just a sense, it can unlock moments and emotions long buried in the mind. Scientists believe this is because the olfactory system—the part of the brain responsible for processing smells—has direct connections to the brain’s memory and emotion centers.

This Direct Connection Between Smell, Memory, and Emotion is a Feature That Reflects Our Evolutionary Past

Typically, when we hear a sound or see an image, the information first passes through the thalamus, a part of the brain that acts like a relay station. The thalamus coordinates which parts of the brain should be involved in processing the sensory input. However, the smell bypasses the thalamus entirely. They head straight to the brain’s olfactory center and  directly connect with the amygdala, which processes emotion, and the hippocampus, where memories are formed. This near-instant connection helps explain why smells evoke such vivid and emotional memories.

At one point in human evolution, all senses had direct access to the brain’s emotion and memory centers. But as the brain evolved and the neocortex—responsible for higher-order thinking—expanded, most senses were rerouted through more complex pathways. Vision, hearing, and touch now rely on intermediary regions to access memory networks. In contrast, the wiring for smell never changed, retaining its direct link to these primitive parts of the brain.

Emotion Before Memory

When we encounter a scent, it often stirs an emotion first and a memory second. This is because, throughout human evolution, emotions have served as our primary guide to the world—whether to avoid danger or seek comfort. For instance, a smell might make us feel uneasy or safe before we even recall where we encountered it. Dr. Rachel Herz, a professor at Brown University, notes that because of this deep emotional connection, “scents can bring back memories that might otherwise never be recalled.” But while these memories feel vivid, it doesn’t necessarily mean they are accurate—our emotions may amplify the sense of clarity we associate with them.

The context in which we encounter a scent also plays a key role in how we respond to it. If the situation is different from where we originally experienced that smell, we’re more likely to feel something strongly, but less likely to recall a specific memory tied to it. Many of the scent-triggered memories we have come from childhood, a time when we were first exposed to a wide variety of smells. These early experiences leave a lasting impression, making certain scents especially powerful in evoking long-lost emotions and moments.

Odors aren’t just triggers for nostalgia, they help us hold onto memories of the people and experiences that define us. 

In light of recent events, particularly the global pandemic, which has left many people without their sense of smell. This reminds us how loss of smell can significantly diminish a person’s quality of life and is linked to depression. 

In a time when so much has been disrupted, scent provides a way to anchor ourselves. It reminds us not only of where we’ve been but also of who we are beneath all the changes. Whether through the smell of a favorite dish or a familiar perfume, these moments of sensory connection allow us to reclaim parts of our identity in ways no other sense can.