I have an enduring respect for the girl who, at 9:16am on Monday morning, barrels up the stairs of the 149 to London Bridge.
I'm not the only person to look up a bit surprised, because you don't see many four year olds alone on the daily commute, and we watch as she pauses, waiting, trying to decide what to do next.
We've all been there: we've all risked it in rush hour, gone up to the top deck knowing the odds but giving it a go anyway, tilting our chin up, peering expectantly looking for a spare seat while also trying to discreetly check why it might be free. And there you are in front of everyone, head bobbing side to side, squinting down the bus. A pointless move at this time of day and everyone knows it, so you have to retreat quietly back down the stairs while, you imagine, the seated roll their eyes at the back of your head.
But she's not like us, this girl, mostly because she's four and unspoken bus etiquette hasn't got into her head yet - so she stands there, waiting patiently at the front by the stairs.
Then her dad appears - but the bus is full, right, so I expect him to look around and see there aren't any spare seats and do that slightly chastising louder voice parents do when they're saying something more for the benefit of the adults around them than the kid, and announce that there's no space, sweetheart, let's leave these good people alone and go back down. But instead the girl - a pink plastic headband made of tiny flowers around her head - looks up at him. And in a quiet, encouraging way - more eyes than voice - he says:
And then she steps between the bulky jackets and belongings, and squeezes into the aisle space between the front row of seats. Their occupants shift slightly at the intrusion, then relax slightly when they see who's causing it, and shuffle their bags about to make space. And the whole time her dad stands there, not apologising or getting in the way, just letting her get on with what I like to think is a daily routine. No one offers to give up their seats, and they're not expected to really, no one expects anyone else to get up.
And anyway, the girl's fine. She's dead centre at the front of the bus, both hands grasping the horizontal rail, eyes straight ahead: transfixed.
She's looking out of that big window, a prime spot between the seats everyone likes the best, because from there it's like the bus is calmly floating through the city instead of whizzing past it.
And occasionally, she just glances back at us - the stupid grown ups with our headphones in, stroking our tiny screens like delicate eggs - giving us this look that says, you're all adults and can do what you want, so why are none of you doing this?
Read more thoughts from London here.