“Am I crazy?” I asked the approaching paddle boarder. “Not at all,” he said. “The water is the warmest it’s been all summer.” His white hair and British accent gave him an air of authority. I wanted to believe him, but my big toe told me that my concept of “warm” was a world away from his.

It was mid-September at Alice Lake Provincial Park in British Columbia. The air temperature was in the mid-sixties, and at 6 pm, the sun was on its way down. I was perched at the edge of the dock, dressed only in my Speedo. No heat to be found anywhere.

Still, I willed myself to take the plunge. I hadn’t been swimming in weeks, and I thought stretching my legs in the water would feel good after the day’s long hike. The paddle boarder disappeared and I was alone again. There was no one around to witness my bravery—or my lack of it.

I jumped in. As the icy water closed over my head, I was transported back to summer camp. Memories of night-time dips and swimming lessons in a lake rushed in as the scent of fresh water filled my nostrils. Gasping from the shock of cold water, I managed to swim out to the beaded line and then back to the dock. Not exactly the 20 laps or so I had hoped for.

Today, as I sit wrapped in wool at my desk back in Massachusetts, the memory of that aborted swim—undocumented and mine alone—and of the visceral, unexpected feelings and scenes from my youth that suddenly flooded back, fills me with joy and nostalgia over and over again.

The rest of our time at Alice Lake is a blur of blue sky, mossy woods, and the amputated stumps of mighty trees felled by loggers. In this case, however, I have documentation.

Back at the campsite, we ate salmon and vegetables grilled over an open fire with mashed potatoes. Dessert was s’mores.

After three nights in the tent, two longish hikes, and the aforementioned swim, we headed south, exhilarated and exhausted.