Bert Hubley was one of the best teachers I ever had. Tasked to instill a pre-chemistry curriculum into the minds of middle schoolers, he threw in ornithology and astronomy, as well, just to keep things interesting. His sky-high expectations were both intimidating and exhilarating, and even those daunted by his style couldn’t help but respect him.

Mr. Hubley cautioned his pupils not to be the sort of people who wander around staring at their feet, especially at night when there’s a starry sky to observe. To mark the end of each period, he’d ask his signature question: “What’s the word, class?” As instructed, we’d respond, “Look up.” (Granted, that’s two words, but whatever. He didn’t teach English, or math, and the message was sound: Look up, people. Pay attention.)

I am often reminded of Mr. Hubley’s tutelage about halfway through my daily walk, as I plod along ruminating on my workday, conducting imaginary, mental arguments with random people, or generally fretting about inconsequential crap. At some point during this unobserved trudge through the neighborhood, a kindly voice will break through the haze to ask: “What’s the word, class?”

And I remember his lesson, and I look up.

It can be a real gift, breaking out of one’s head.

Thank you, Mr. Hubley, and to all the great teachers out there. Your lessons have the power to make a lifelong difference.