Traffic was light this morning as I drove the familiar miles North on 128 to my office in Burlington. Arriving at 7:30, I found the parking lot mostly empty and pulled into a spot near the side door where I always entered the building on my way to my cube on the second floor of the Nuance Communications building.

I was relieved at how normal it all felt. I had wondered whether it would be strange or sad. After all, it would be the last time I’d pull into that parking lot, enter that door using my badge, climb those stairs, and set my company-issued laptop down in the cube with my name on the door.

When it comes to quitting, I find myself with no shortage of glib stories to explain why I’m walking away from a pretty good job that provides security and routine, but none of those stories feels quite right.

A few days ago, I told someone that my life felt like an old radio whose dial was stuck between two stations, with slick pop music playing simultaneously with snatches of a talk show, and the whole thing distracting in the extreme. Yesterday I told someone else that it feels like I’m actually trying to solve the same problem in both my work life and my running life: how to overcome a pathological lack of oxygen flowing to my working muscles. I’ve mentioned to others the standard fantasies about having more time for all “the important things” — the new grandkids, a healthy exercise routine, studying Japanese, coaching, writing that book that I have in me, finally cleaning out the attic.

Those are all true, but any one of them and even all of them put together don’t really add up to a reason that I’m leaving high-tech and my commitment to a full-time job for the first time in 35 years. The truth is, I don’t know why — I feel like I have to quit to find out.

I had a realization a few years back that the essential currency for successful running was time. It takes time each day, and it takes a lifetime of slow, steady progress to become the runner you want to be. But most of us rush it; no matter how good our intentions, we cut corner after corner, and we pay the price — maybe not today, but eventually.

And as I get older, my relationship to time is changing surely. For one thing, as it becomes scarcer, time feels far more valuable to me. I feel a great impatience to make smart choices about how I spend my time. For another thing, my ability to use my time efficiently is declining. It takes me a lot longer to cover any distance. It takes me a lot longer to do my chores. I get tired more easily. If I’m not careful, I use up all my energy before I’ve done the things that I swore were the most important.

I thought seriously about quitting 18 months ago. Most of my friends urged me to do it. Sometimes I thought they knew me better than I knew myself, and I felt like I was letting them down by staying put. Other times, I wondered if they were the ones looking up to where I stood on the ledge, urging me to jump. Or maybe they just wanted me to have more time to devote to the blog again. Whatever the truth of the matter, they were unanimous in expressing confidence that my worth was not dependent on my employment status.

In all honesty, I don’t know what I’m going to do next, or rather, I have hunches about what things I’ll be doing, but very little sense of the shape it will take. That’s OK. The uncertainty feels like a necessary element right now, and I’ve always enjoyed trying to bring some order out of chaos. Maybe I needed to create a little (or a lot) more chaos to challenge myself. We’ll see, I suppose.

In any case, I know what I’m going to do tomorrow. I’m going to run. Not far, not fast, but one foot in front of the other, like always. I’m looking forward to finding out where those tentative steps  take me, and once I find out, you’ll be the first to know.