Jeff Novotny’s parents moved to Nashua in 1972 after his father’s company set up shop in Chelmsford. In looking for a place to raise their three sons, they couldn’t resist settling just over the New Hampshire border, where they’d enjoy the benefit of no sales tax and the bonus of being within an hour’s drive to beaches, mountains, and cultural centers like Boston.

Novotny recalls that no matter what time of year it was, he and his brothers would spend their days outside with other neighborhood kids, either in their own backyard, which was the perfect size for baseball games and therefore a main gathering spot, or at the nearby playground. “We were outside all day every day. Even if it was bad weather, we were out,’’ he said.

It was all they needed. “It’s amazing, when you’re a kid, your world is so small.’’

Now, as an adult, Novotny is rediscovering the city as a mail carrier for the US Postal Service — and it’s a much bigger world than he once thought. Not only is he finding neighborhoods and streets he never knew existed, he’s seeing just how much the city has changed. He particularly enjoys when he is sent out on a route that brings him to the renovated mill buildings downtown, where he can look at photos displayed in the lobby of them in the 1800s, when the Merrimack River helped power the city’s booming textile industry.

He’s also a fan of delivering in his old neighborhood and running into former classmates.

“I like the nostalgia of delivering to the house I grew up in. I like seeing the names of people I went to school with, knowing it’s their parents and they’re still around,’’ Novotny said.

And this daily, on-the-job trip down memory lane has brought him back to his youth in more ways than one: Once again, even when the weather is bad, you’ll find him outside.

Chris Morris, the Globe’s Travel and Food editor, can be reached at christine.morris@globe.com.