I recently got back from a road trip through New England with a friend.  The trip itself was fun – scenic drives, picturesque towns, and some beautiful remote hikes.  But one of the things that made the strongest impression on me happened the day before we left.

My friend had some business to take care of before we headed out, so I spent the afternoon strolling around Cambridge and Boston.  It’s a good town for walking, with handsome campuses interspersed with humbler neighborhoods of houses and shops.   That day, it was clear and unseasonably warm out, and the whole town turned out to enjoy the weather after a record-breaking winter.  Everywhere I went I’d see young, thin, well-educated people – a pretty different demographic than I’m used to in West Philadelphia.

On the subway I’d see students with their noses buried in books or Economist articles on their iPhones.  On the banks of the Charles I saw young couples strolling hand in hand, or lounging on the grass watching the antics of a group of boys on paddleboards in the river, who were whooping as they got splashed with frigid water.  In cafes I’d see small groups of grad students with heads together, talking animatedly over their beers.  And everywhere, there were the ubiquitous joggers, running from nowhere to nowhere in easy loping paces.

And as the afternoon dragged on, I noticed a little voice in the back of my head start saying things like “Hmm, I wonder what that gaggle of students is working on?  What’s that guy learning about right now?  How did that couple meet?  Hmm, maybe I should swing by the gym myself,” and so on.  Nothing terribly obtrusive, but just a tiny low-level paranoia that I was missing out on some important improving experience that these other people around me were taking advantage of.  It was a funny feeling that I hadn’t really encountered except for back when I was in college.

But when I sheepishly mentioned it to my friend, he immediately recognized it and said that he felt it all the time, walking around the campus of business school and seeing other highly competent people going about their business.  And really, it was no bad thing.  This brief experience did, in fact, inspire me to hit the gym more seriously once I got back, and to bang these musings into essay form on the flight back home from Boston.  Certainly, I could imagine it growing into oppressive insecurity if it were stronger, but on the whole it resembles exercise – a hormetic stressor that makes you stronger.

Paul Graham wrote an essay about what messages cities send to ambitious people.  I suspect that something like this is the actual medium by which these messages get sent.  Nothing obvious, just a constant reminder that other high-level people are out there improving themselves, and that you’d better keep doing the same or else fall behind.  And this is what helps to produce both talented individuals and talented ecosystems.

Everything else is an epiphenomenon.  All the ads on the subway exhorting people to work for a company trying to cure cancer, or to go back to school to get on the cutting edge of robotics, the indie bookstores and small museums, even the tech companies that get started, fundamentally derive from the existence of smart people whetting one another’s appetites.  I didn’t notice its absence in Philadelphia, but I certainly noticed its presence in Cambridge.  I suspect that this feeling of “fire in your belly” is underrated as an ingredient in the good life.