A couple of days ago, I found myself on the downtown D train. Happy to find a seat in a crowded car, I was looking down, fiddling on my phone, as one does. When I looked back up, who was sitting across from me? Pioneering hip hop DJ/personality/producer/manager Kool DJ Red Alert, that's who. Like many New Yorkers, I have an unwritten rule that I never acknowledge famous people. But I occasionally make an exception for someone who is kind of a niche celebrity and who (in my mind at least) might actually take pleasure from being recognized in an unexpected place. So I called out, "DJ Red Alert!" He looked my way. "Appreciate you," I said. He nodded without smiling. I went back to scrolling on my phone, thinking maybe I had erred in bothering him. But when we reached the next stop and Red Alert got up, he took a detour to give me a fist bump as he was getting off the train. The whole thing made me happy to be a New Yorker.