Standing on the bank of a trout stream, you’re probably used to thinking about how three of your senses are focusing on the fishing. Whether it is wholly conscious or not, you’re relying on feeling, hearing, and seeing what is around you.

Sight is obvious. It is necessary to position yourself. Identify feeding lanes. Figure out what bugs are in the water.

Listening is also vital. The telltale sips and splashes of feeding fish are some of the subtlest yet most invigorating sounds to anglers.

Touch does a lot. Everything from feeling the wind that will affect the cast to perceiving the temperature is communicated through your nerves telling you what is happening.

Those three senses are what you can count on using when you’re trying to catch fish. Your body is constantly working, sending data to your brain allowing you to synthesize the unfathomable number of variables that go into fly fishing. Taste isn’t really a factor, unless your beverage or snack of choice is a must-have.

Smell, on the other hand, can be a powerful sense.

This past week I was multitasking in Pennsylvania. I had some work, personal, and fishing business to attend to. One such activity involved stopping by a former fishing haunt to take some pictures. I’ve been planning on doing some writing that features the spring creeks I frequented for a number of years, and I also needed some good stock imagery. A friend and I stopped at the headwaters of my favorite creek, and I began to get to work photographing some shots I thought I could use.

I walked up the road to a bridge that crossed the creek. On top of the bridge, I took some pictures both upstream and down. The water looked great, and I even spotted a few little brown trout. There was a real desire to make a few casts, but I knew I didn’t have the time. I wanted a good shot of the creek meandering up through a willow-lined meadow, so I thought I’d hop down off the side of the road and get down at creek level.

I jumped the guardrail and I instinctively crouched to absorb the four-foot drop. It put me right where I wanted to be, but it also put me someplace I didn’t expect.

As soon as I hit the ground, the combined scent of the creek, the streamside vegetation, and even the road brought memories flooding back. It was unexpected. Powerful. Emotional.

Psychologists and neurologists have long understood the strong link between our sense of smell and memories. Physically, our olfactory bulb has a direct connection to the amygdala and hippocampus. These brain areas are stimulated when we recall memories or experience emotion. A perfume, a food, or a tree can quickly snap us back to a place or sentiment in ways that even sight can’t necessarily replicate.

For fly fishers, angling is full of smells: The resin of balsams in the north woods. Muddy flats on low tide. Algae covered rocks baking in the sun on the river bank. Waders that haven’t quite dried out from the last trip. The duffle bag that bears some food and flotant stains. While these scents don’t often translate directly to angling technique or calculating fly presentation, the science underlines their place in cementing the experience for us.

And the experience is often why we fly fish.

I was – I am honestly surprised that I was impacted the way I was. It was probably the perfect storm: I was in a place of dead air on a warm afternoon. Buffered against a concrete bridge, the delicate odors streamside vegetation and the crisp aroma of cold spring water was simply sitting there. And I dropped right into it.

I thought about the biggest trout I caught on the creek; how I had to drift my midge downstream under cover, and then be patient to not pull the fly out of her mouth when she gently nipped it. I remembered the conversations I had with fishing buddies about trout and things much more significant. Even in that moment I was taken back to those times. Then I thought of everything that had happened since. It was a lot for less than a minute, crouched next to a guardrail.

Not being a neurologist, I’ll take the professionals’ word for all of that olfactory-amygdala stuff. But I buy into the practical conclusion. I know the coniferous smell of a mountain brook trout stream, the hot over-fertilized bouquet of subdivision ponds, and the brackish whiff of tidal marshes. When I am already thinking about previous experiences in those locations, the scents add to the reminiscing. But when my mind is somewhere else, those scents can and will jostle my memory in a startling and amazing way.