Dear No. 12 Bus:

My 4-year-old son and I were walking north on 23rd Street the other day when you barreled past us, heading south on your usual route. When he spotted you, he couldn't contain himself.

"DAD!" he yelled. "That's OUR bus!"

And I had to laugh, No. 12, because he was right. Sure, two other routes — the 7 and the 40 — swing through our Fitler Square neighborhood, but you are the route that makes the city make sense to me. Other folks may get their bearings according to the Market-Frankford or the Broad Street lines, and real seasoned city dwellers may have a complete map of SEPTA's entire range of services imprinted in their heads, but as for me: When I know where I am in relation to the 12, I know where I am in relation to home.

Understand: My wife and I didn't know Philly at all before we moved here in the summer of 2008. In short order we a) had our son and b) sold our car, ready to embrace Center City's renowned walkability. But there were days when walking wouldn't do. When it was rainy. Or when we needed to go a little farther than our legs would carry us. And you were how we started to expand our understanding of the city's geography beyond the few square blocks around our apartment.

At first, you took us east, in the direction of how Philly wants to think of itself. Past the shopping row of Walnut Street, through the sprawling campus of Jefferson University Hospital — a portion of the route I'd come to know especially well during a painful year of surgeries — down to Society Hill, just a few steps away from great food and drink in Old City, or America's history at Independence Hall.

(It should be said, too, that you also taught me, in your special SEPTA way, to be patient. There are countless times that I've stood endlessly on Walnut Street, watching three different buses on the 42 route slide by before a single overcrowded 12 came along. I forgive you. For now.)

Gradually, we understood, too, that you also run south and west — through Grays Ferry, past strip malls and a giant recycling center, through boarded-up neighborhoods and finally to 50th and Woodland. This is not fun, or glamorous, but it is also Philly. And when passengers steps off the No. 12 at this end of the line, they are confronted by the pain this city is made to bear: A mural, stretching around the block, includes portraits of many of the neighborhood's young people who have lost their lives to violence over the last 20 years.

What can I say? Philly isn't just the great restaurants of tourist ad campaigns. It's not just the war zone the rest of the country often sees on TV. It's both of those things, and a lot more. You've taught me that there's more to this city than I've had time, so far, to understand. Luckily, though, you're also always there to help me get my bearings.

—Joel

Joel Mathis is a Kansas-bred freelance writer who came to Philadelphia to live in the "big city" and found this place doesn't feel too different from his Midwestern small towns.

This essay was originally published on the blog Philly Love Notes.