I’m turning 40 this week, so it feels like a trite, but also necessary, step to ruminate on aging and the process of growing older.  One question I often ask myself is: “do I feel old?”  The answer, of course, is that it depends. 

Physically, I certainly notice wrinkles on my face and blemishes on my hands, where the skin was once smooth.  And my back aches more often than it once did.  But I also feel that I’ve done a good job staying in shape—my resting heart rate is low, I’m not overweight, and I don’t find the prospect of a hike (even one where I must carry my toddler half the way) intimidating.  And yet, I increasingly understand what some older folks have told me about being a young mind trapped in an older body– sometimes, my body can’t keep up with what my mind intends for it.  I particularly notice that I’m not quite as flexible as I once was– and trying to work on flexibility is a good goal for the years ahead.  The only thing that irks me is the skin on my hands—it looks older, and that bothers me.  But I’m a decade or two too late to improve my skincare regime, so I just soldier on and try to maintain adequate care now.

But if I’m a young mind in an aging body, am I still a young mind?  That’s what (metaphorically) keeps me up at night.  A study in the Proceedings of the National Academy of Sciences that analyzed a huge dataset of chess matches suggests that rational, thoughtful mental acuity reaches a peak at 35 and stays there till about age 45, when it begins to decline.  An article summarizing other studies and breaking out different mental aspects suggests that short-term memory and information-processing speed have both begun to decline by ones’ thirties, although emotional intelligence tends to not decline until around age 50.  Another research study in the journal Psychological Science breaks out a dozen or so aspects of mental acuity; the short answer is that most aspects peak by age 30, with vocabulary and comprehension still growing until about age 50.

So, assuming I’m not a 3-sigma outlier (unlikely), I’m probably mentally past my prime in most areas—a terrifying prospect for an academic and a geek who places so much of their self-image into their mental facilities. I don’t know if it’s comforting or concerning that I haven’t noticed much of a decline—about the only area I am viscerally aware of declined performance is in my twitch reflexes when playing multiplayer computer games, where I now gravitate to the characters whose performance depends more on thoughtful placement and positioning, rather than twitch responses.  But, I need to practice acceptance of my changing acuity–  many studies have found that “brain training” does essentially nothing to stave off cognitive decline (although it can improve performance); though some studies suggest diet and exercise may slow mental decline.  Even more reason to focus on cardiovascular health, flexibility, and good dietary habits!

The other aspect of aging that sometimes bothers me is the prospect of losing the ability to effectively travel and experience new cultures and marvels.  Travel is one of my greatest joys in life (which deserves a post of its own in the future), and maintaining and preserving my ability to travel is a key consideration to me when it comes to aging gracefully.  Yet more of a reminder to keep my health up (in fact, as I write this, I’m jogging along on my home treadmill desk, which makes typos more likely, but nicely gets my heart rate up).  I know that my time to travel and enjoy the world is limited (see the “Andrew’s Life in Weeks” figure, derived from this Medium.com post), and so I’m using the excuse of turning 40 as a milestone to prioritize that travel: whereas my goal was once to do a big, international-type trip once a year, I now intend to do two such trips a year, minimum, in addition to more domestic adventures (whether solely family-focused, or for biochemistry conferences with fun tacked on).  Assuming I keep relatively good cardiovascular and other health for another 25 years, that’s at least 50 more memorable trips—which sounds like a great goal to me.

The last aspect of aging I wanted to touch on is regrets.  Traditionally, there’s an expectation that as one ages, they will face their mistakes, and learn from them, but also convey regrets on opportunities not taken.  I guess I’m lucky, then, in that my regrets (while not absent) are relatively few.  They largely concern not spending enough time with my departed mother, Sonja, and not working to preserve and strengthen friendships that I’ve shed along the way.  Friendships have always been hard for me; I don’t seem to have the knack of staying in contact with lots of people, or bridging that middle-ground between “dearest confidante” and “casual acquaintance” into the realm of “decent friend that you see occasionally”.  That said, I am especially happy that despite that infirmity of character, I have an incredible stable of good friends and wonderful family.  And moreover, I have an incredible wife and kids; they bring me joy every day and make each new day an adventure.