Little things mean a lot. William brought out the baby's chair and buckled it in the back seat of the car. Then he jumped into the front and drove his family away from the hospital. No chauffeur, no attendants, a normal young family.
Sometimes change is so right that it goes unremarked. Yet if the Duke and Duchess of Cambridge had emerged from that hospital with a nanny carrying their baby and a footman holding open the rear door of a Bentley, we would not have been surprised.
If they had given the waiting crowd no more than a fleeting wave before stepping into the car, and television's best view of the baby had been of a bundle dimly glimpsed through the window, commentaries would have been understanding.
It is hard to express what William has done without diminishing it to a social statement. Neither he nor the equally normal Catherine appear to intend their actions to be a statement of anything except that this is the way they want to live.
Nothing in the manner implies an intended rebuke to royalty, both seem to enjoy the formal work they need to do, and do well. When they go home they want their own life. That's all.
When they said as much in an interview before their wedding it didn't sound likely or possible.
But the evidence was in front of our eyes this week when they brought the baby out to the crowd in the street.
"How does it feel?" someone asked. "I think any parent will know what this feeling feels like," said Kate, as the press and public insist on calling her. That is our right, royalty is our creation.
What is it about the royal family that is so captivating? I used to think it was just the palaces, the pageantry, the opulence of their surroundings and the wonder of what it must be like to live that way. But that is not all it is.
The essence of royalty's lasting appeal is probably that they give the world a family that everybody knows and we can know them their entire lives. From birth to death, through childhood, adolescence, relationships, marriages, babies, break-ups, anniversaries, we know them whether we admit it or not.
They meet our need for a common reference point for talking about life. That is a subject best discussed with real names, not abstract terms. Notice how we don't use their titles in conversation?
Kate was right, every parent knew exactly what she was feeling when she could hardly take her eyes from the baby's face. Every new father knows what it means when you get in the car and it hits you, you have a family.
Even Charles struck a resonant chord when he expressed surprise at how good it feels to become a grandfather. I know precisely what he means but have no precise word for it, which is why it helps to have royals for common reference.
I wonder at what age little George will realise the exalted public role he has been awarded at birth and that it means he cannot be entirely his own man. I wonder how you raise a child with that realisation.
The only way to keep his personality grounded, I imagine, is to stress that it is a job larger than any person born to it, and that anybody capable of doing it is humbled by it.
You couldn't tell a child these things, you could only exemplify within the family a healthy grounded attitude to yourself and your respect for the position. William might have inherited his engaging ways from his mother but his ability to be himself in his public role might owe more than we know to his under-rated father.
Charles, for all his ingrained formality and inhibitions, has a brain. If he gets to be king before his dotage he could be an interesting one.
It is possible that he has given creative thought to the constitutional dilemma of Canada, Australia and New Zealand. He knows we no longer refer to the "Queen of New Zealand". The term sounds wrong, for her and us. She does not do what a head of state does, she is not here.
But we are reluctant to change, fearing perhaps that we would lose some emotional connection. We wouldn't.
The constitutional tie played no part that I could hear in conversations about the birth this week.
We could replace the Queen with the Governor-General at all references in constitutional law tomorrow and nothing would change in real life. We would follow royalty with the same interest, especially now. It is going to be important that this friendly young family can find something like a normal life in that gilded cage.