The Queen got it right - and Theresa May got it wrong. Everyone agrees that Britain's 91-year-old monarch, going to meet victims of the Grenfell Tower disaster, responded much better to the tragedy than Britain's Prime Minister did.
But trying to be fair to Mrs May - not an exercise I often undertake - the Royal Family, and particularly the Queen herself, have had the chance to learn from lessons past. Not only the lessons learnt after Diana's death (the twentieth anniversary of which we commemorate this summer), but one from much earlier in her reign. It's a case of 'third time lucky', basically.
It was in the mid-1960s - the second decade of the Queen's reign, when the initial enthusiasm that had greeted her was beginning to die away. The monarchy could no longer rely on unquestioning support - and in the changing times, the Queen's own old-fashioned style of repression and restraint could look like coldness or weakness.
A case in point came in 1966, when an avalanche of mud and debris cascaded onto the Welsh mining village of Aberfan, engulfing its primary school, killing more than a hundred children and 28 adults. The Queen, urged to go immediately to Aberfan, refused.
She did so for the best of motives. The arrangements for her visit, the need to provide security, might distract from the rescue effort. What if she caused rescuers to miss 'some poor child that might have been found under the wreckage?', she asked. This was after all a woman who had grown up during the Second World War, whose parents visited bombed-out areas of London where - in an age before today's technology - ears strained to hear the faintest cry might be the only way to find survivors in the rubble.
When the Queen did visit Aberfan a week later, her emotion was palpable, sorry, as she told the villagers with tears in her eyes, 'I can give you nothing except sympathy'. Perhaps those tears are the real point - another way in which, even then, she was showing in better colours than Theresa May.
But all the same, it seems appropriate that visiting the survivors of Grenfell Tower, the Queen was accompanied by Prince William. Not just himself a former Air Ambulance pilot, a member of the emergency services, but a son of Diana, Princess of Wales. And today, you might almost say that any public figure giving a caring response to a tragedy does so trailing the faint perfume of Diana's memory.
It's not just about Diana's own responsiveness, shaking hands with AIDS victims and hugging orphans. It's about the lessons learnt that summer of 1997, when (in the words of one tabloid headline) British people begged Britain's Queen to 'Show Us You Care'. We all know what followed - that the Royals finally left Balmoral and came to meet the crowds in London, that a flag flew half-mast over Buckingham Palace, and the Queen, having broadcast to the nation, spontaneously bowed her head as Diana's coffin passed by.
All those events and more will be rehashed this summer as the 31 August anniversary draws nigh. But perhaps the real thing to be noted about that summer is this - that the changes of practice into which the Royal Family were persuaded back then have never gone away.
It's notable how quickly, in the weeks after Diana's death, royal popularity was restored. By November, the nation could happily celebrate the Queen and Prince Philip's Golden Wedding Anniversary. The royal establishment had been jolted out of a decades-old complacency, their Queen's subjects had been given a catharsis. We had vented our dissatisfaction, they had taken it meekly. They promised to do better, effectively - and they have, This summer shows it clearly.
Diana's legacy - whether or not it's one she would have wanted - may be the modernised, the more visibly emotional, Royal Family that is breasting the 21st century.
Sarah Gristwood is the author of the forthcoming Elizabeth: The Queen and the Crown (Pavilion).