Every night, before she retires, the Queen sits down to write her private diary, dashing off detailed and colourful accounts of all the day’s events.
Friends say Lilibet started these journals when she was just a girl. But they would soon become an indispensable part of her record-breaking 70-year reign.
Because the secret diaries of Elizabeth II are the guardians of her most private thoughts and feelings.
They are the one place she doesn’t have to compartmentalise herself into monarch or mother, institution or individual.
But that was the extraordinary task that befell the 25-year-old Princess Elizabeth on February 6, 1952.
King George VI was found dead in his bed on the Sandringham estate in Norfolk.
Some 4,000 miles away in Kenya, his daughter woke in a treetop hotel blissfully unaware that she was now Queen.
A few hours later, Prince Philip broke the news and Elizabeth burst into tears.
But by the time she arrived home the next day her raw emotion was already concealed behind the invisible armour of sovereignty she has relied on for seven decades.
Politicians were hailing her the new Gloriana and post-war Britain was expecting the dawn of a Second Elizabethan Era.
Imagine the weight of responsibility on her shoulders at a time when she just wanted to hug her children, comfort her mother and mourn her beloved father.
You can’t help wondering what maelstrom of emotions the new Queen shared with her diary 70 years ago today.
Or how many times since has she confided the pain of putting duty ahead of herself.
Early in her reign, Her Majesty met US First Lady Eleanor Roosevelt, who asked an aide how she juggled the burdens of duty and motherhood. “Oh,” sniffed the secretary, “The Queen is very departmentalised.”
But Mrs Roosevelt left the palace wondering “How does one departmentalise one’s heart?”
It’s something we have all been wondering recently as the widowed 95-year-old Queen has had to deal with the sex scandal surrounding her favourite son and the shenanigans of her petulant grandson, Harry.
But today we can help Her Majesty turn a page and ensure that the next four months are filled with happy and colourful memories.
As her Platinum Jubilee begins we can start unfurling the bunting, putting out the flags and painting the nation red, white and blue.
And when that four day holiday arrives in June we can throw the most enormous party for our remarkable, resilient, record-breaking monarch.
Sunday, June 5 has been dubbed Thank You Day and a host of institutions like the Scouts and Guides, the RVS, the FA and the Rotary Club are joining forces for a gigantic celebration.
And now a campaign is under way for a royal “Thank Holiday” every year.
A chance to mark the Queen’s lifetime of service while also recognising our community heroes.
I’m sure Her Majesty will thoroughly approve – and make it a red letter day in her diary.
