There are some things you see every day that you just come to expect - commuters don't talk to each other, bus drivers are grumpy, if a pedestrian or cyclist gets in the way of a London driver they're liable to be hooted at, people don't give up seats on the Tube any more...
So that makes it all the more refreshing when someone behaves in an unexpected way - and last week I saw something which put me in a good mood for the rest of the day.
Being early November and the clocks having gone back, it was dark and miserable by the time the evening rush hour began. I was leaving the office and heading for the station along a busy London street.
As I walked, I noticed that the traffic lights ahead of me were red. There was a cyclist at the front of the queue of traffic, and behind him was a bus. Suddenly, one of the lamps fell of the cyclist's bike, and as it hit the floor it sprang apart into several pieces.
The cyclist scurried about trying to pick up the pieces of his lamp before the traffic lights changed, but he was too late and had to rush to the side of the road, wheeling his bike with one hand as he clutched a few broken pieces of his lamp with the other.
I saw all this almost without registering it, but then felt very sorry for the cyclist as I heard the inevitable hoot of a horn.
For once, though, it wasn't a motorist getting impatient with a cyclist. It was the driver of the bus, and he was beckoning the cyclist over and pointing to a large part of the cycle lamp which lay on the road in front of him. He was also resolutely keeping still and preventing the traffic behind him from moving, so that the cyclist was able to run forward and pick up the last piece of his light.
It gave me a warm glow to see the consideration that this bus driver gave to the cyclist - all the more so, probably, because of the treatment that I've had from bus drivers in the past over seven years of cycling wherever I went in London.
It also made me think - that small act of courtesy probably made the cyclist's day. Just seeing it happen made my day. It's so easy for each of us change the course of someone's day - for better or for worse - without even realising it.