We recently had four inches of snow in Washington, not much, actually, but enough to bring the city to a halt. Record-breaking cold weather, down into the teens and even single digits, has accompanied the snow, so it has stuck around for a while.

True, we would hardly have noticed this weather when we lived in northeastern Minnesota, but it brings up a longing for the winters there. My memories of cross-country skiing through the forest near our house are among my happiest.

The city was beautiful, however. Marja and I stretched our regular evening walk to about an hour, enjoying the snow hats on the front-lawn bushes, the empty streets, the wind swirling down the main corridor of our local business area, one house with Christmas-tree lights still on the pine tree in its front yard, and the occasional person struggling against the wind and the cold.

When the temperature is this low, the snow gets crunchy underfoot, evoking memories of walks in Finnish winters where we also lived for some time. When it's this cold, the snow is no longer slippery, nice for an old man whose balance ain't what it used to be. It was absolutely glorious to be out in the quiet city.

As we walked, however, I noticed that I kept leaning forward. Marja noticed it to.

We always walk quickly to get the exercise as well as our nightly togetherness, but Tuesday evening, I almost couldn't help speeding up. Unintentionally I kept leaning forward, and my legs seemed to be hurrying up to catch up to my upper body, which seemed to be dragging my legs along. I stepped off a curb and almost tumbled forward into the street. I didn't fall but only because Marja and I often hold hands, as much for balance as for tenderness.

Before I was aware of my cognitive decline, I would hardly have noted an isolated instance like this. With my impairment, however, my medical mind switched on, and I thought immediately about Parkinson's disease. One of its signs is a "festinating gait," which is one image I have from medical school: a guy pulled faster and faster by his upper body. Parkinson's is often a cause of dementia, too.

Naturally, I googled it when we got home. It turns out, however, that my gait didn't really meet the criteria to be festinating. I'd forgotten the other elements it comprises: stooped position; short, shuffling stride; absence of an arm swing; difficulty starting and stopping; and so on. It also turns out that a festinating gait doesn't show up until late in Parkinson's when many other symptoms would have become obvious.

The mental jump to thinking about my impairment is understandable, I suppose. My diagnosis is uncertain, different diseases have different prognoses, and I'm a doctor with a natural curiosity.

But I also wonder if it's an unhealthy preoccupation with the future.

In the months following my diagnosis, I felt a wonderful freedom from concern about the future. I lived more in the present, more in tune to others and the world in general.

It was wonderful.

Some of that remains. On the other hand, I find myself now, twelve months later, a little less in tune with the others, more often preoccupied with past and future.

Is this thinking about Parkinson's a "preoccupation" or something less neurotic?

I don't feel worried about the future, mostly interested in it. It's a mental challenge to put together all of my symptoms and test results, and wonder about the different futures. So I don't really feel worried.

In any case, this is my present moment. Wondering about what's happening now, even wondering about my future is what I'm doing in this present moment. And the present moment is where I want to live.

Editor's note: David's journey with Mild Cognitive Impairment was chronicled in "Fade to Blank: Life Inside Alzheimer's," an in-depth look at the real lives of families impacted by the Alzheimer's epidemic. His story continues on his personal blog on AgingCare.com.