Last month, I was stopped at a red light watching pedestrians stream by as another car waited impatiently on a side street to turn, nudging towards the intersection.
There were quite a few elderly people crossing in that way elderly people are often forced to traverse a busy street; like a hyena is stalking them, anxious of the dangers posed by aggressive or careless motorists when they lag behind the herd.
As I watched, a woman in her mid-40s passed in front of my bumper and something drew her attention to a slow-moving old gal chugging away next to her.
Perhaps the old lady was breathing heavily, or her walking cane had lost its rubber tip and was making a dragging noise on the asphalt. I couldn't hear, I had Boz Scaggs turned up to 11 in my car.
The younger woman literally stopped in the middle of the street and the old lady surged past her, shuffling towards the sanctuary of the pavement. The younger woman, now walking slowly behind her, shepherded her to safety.
The younger woman's unspoken message to the impatient driver waiting to turn was: "Do not beep this lady, don't try to squeeze past her before she's safe. I will be the last person off this road."
Okay, I'm assuming that was her message, because as soon as the old lady reached the footpath, the younger woman returned to her normal walking pace and blazed off. Nobody, especially the old lady, was any the wiser.
I sat in my car and thought about the sort of person who'd do that. Who instinctively reacted to protect a weaker stranger in a way that brought them no acknowledgment or thanks, nor the other person embarrassment or obligation. Her actions were designed to go unnoticed.
I had to fight the urge to drive ahead of the woman, park my car and get out to tell her she was my hero. But I didn't because, well, apparently men don't have heroes who are women, if you listen to some social commentators.
There's a short doco doing the rounds called Overview about the "Overview Effect". This is described as the "cognitive shift in awareness" that happens to astronauts after they see earth from outer space.
Viewing our globe from "without", astronauts are uniformly overwhelmed by the fragility of our planet; the fact that we're just a tiny blue-green spaceship floating in infinity and all that protects us from the cold annihilation of space us is a flimsy layer of atmosphere.
As the astronauts orbit, concepts of nationality and race dissolve, self-interest dies and they return to earth profoundly awed by how completely every species' fate on this planet is linked.
Somehow, I don't think I'd need to explain that notion to the woman who shadowed the old lady across the street.
As a culture, we've long been fascinated by the myth of superhumans and superheroes - people who can supposed save the planet single-handedly.
I reckon the only myth is that they can do it by themselves. Not that they exist, because last week I watched one in action. I suggest Boz Scaggs for her theme music.