There was a guy in a red shirt who always sat in the middle of the bus. I never saw him get on or off. When I first saw him the shirts were muted greyish pink, but every day, he wore a different shirt, and a little more vibrant than the last one. The effect wasn't noticable from day to day - I only really noticed after spending time off the bus.
We never really talked much, beyond a polite smile and a nod every day. Years of friendly nods, though, can bring a different kind of intimacy.
Eventually, I got my own car, but I noticed the exact same bus on the freeway today. There was a brilliant, almost blinding red light shining from the middle of the bus. I tried to wave hello, but there was too much traffic and I don't think my old red-shirted friend noticed me.