The more walks I take downtown, the more I compare them with my walks in the suburbs — the pace, the people, the places.

Yesterday’s was an outlier but also an example: A helicopter buzzed the Mall, breaking through the music in my ears, annoying me. I vaguely wondered if I should be concerned. A truck bomb? A heightened security alert? (Do we do the colors of danger anymore? I forget.)

As I made my way back to the office, I found Constitution Avenue blocked. That phalanx of bicycle police I’d seen earlier, they were just the front guard. There were uniforms everywhere. No one would be crossing the street anytime soon.

You’d think I’d be motorcade weary by now, but I’ve seen very few and none for this president. So for five minutes I was a tourist like the others standing at my corner — only without a camera or smart phone in hand. And when the black cars passed, motorcycles in the lead, ambulances bringing up the rear, sirens blaring, all the trappings and pageantry — I wasn’t listening to the music in my ears anymore. I was completely caught in the moment at hand.

I wasn’t intending to take a power walk yesterday. But that’s what I did.