It's not just my mind that makes me feel old. It's my body, too.

For the last several years I've had a permanent numbness in my feet caused by a neurological condition known as "peripheral neuropathy." It makes it difficult for me to sense anything on the skin of my feet. It's as if I were sensing through a thick piece of cloth, as if I were wearing socks.

Fortunately, it's not a progressive disease and mine has been stable for a number of years. The worst part is that the nerves responsible for telling my brain just where my foot bones are in relation to each other (the proprioceptive nerves) are also affected, so I don't quite know where my feet are, which means I stumble constantly and lose my balance easily. I don't know if the worst part is falling into somebody I'm talking to or swinging wildly for a couple of steps as I regain my balance.

So in addition to this declining memory, I feel physically unsteady, too. I sometimes feel elderly, especially when the person I'm talking to reaches out and steadies me or when I stumble over nothing. (Marja and I hold hands on our evening walk. It's not just cute; it would also protect me if I tripped.)

Just to be clear, I know I'm not elderly in either my mind or body. Marja and I backpack into high mountains, carrying our supplies as we hike for a week. Despite the city traffic, I still bicycle everywhere I go (my overall balance is fine; I just can't find my feet). I do over thirty push-ups most mornings, and so on. And I still teach, lecture and lead groups well. But in a society that seems to value youth over everything else, it's a struggle not to feel less-than.

Mostly it's the same old problem: I'm still hanging on to a picture of myself from twenty years ago when I was an athlete and could calculate most everyday math problems in my head. As I've written in this blog several times before, however, a sure path to unhappiness is to hang on to the self I used to be.

I'm sixty-nine, my memory is shot, I'm confused from time to time and I stumble over cracks in the sidewalk. And unless I think I'm supposed to be different, I'm fine with it.

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.