Late in my time at No. 10, I realised that I was unlikely ever again to be in such close proximity to extraordinary people. I was also spending too much time on the road and in airport lounges, too far from my new son, Charlie. He had become habituated to my strange life. I once spent an hour advising the prime minister on our troop numbers in Afghanistan while visiting ‘Monkey World’, a soft-play zone in Bromley.

By this stage Charlie had got used to me picking him up from nursery and promptly dropping him off to have a bath and dinner in Downing Street. Having been sick all over his clothes in the car, he once turned up at Chequers completely nude. With characteristic tact and professionalism, the housekeeper commented that it was the first time a guest had arrived naked. Charlie had then interrupted a Hillary Clinton press conference by jumping around loudly. The Secretary of State asked him, ‘Charlie, are you a rabbit?’, and was told with a sterner voice than she was used to hearing from most leaders, ‘No, I am a monkey.’

Missing my son during the long summits that diplomats force in to the diaries of leaders, I began to collect advice for Charlie from the extraordinary people we were meeting. I’d ask them what they would want Charlie to read on his 14th birthday in 2020.

As the project gained momentum, those I asked would take more time over it. Bill Clinton wrote his advice out in draft and copied it into the book in beautiful and careful handwriting. George W. Bush took the book away with him, and returned it with his entry and a nice note about how much he had enjoyed reading what others had written. Mikhail Gorbachev got quite emotional composing his entry. Barack Obama commented that Charlie would either be very rich or very clever, depending on whether he sold the book or read it.

The advice varies from the idealistic to the practical, and in many cases reveals much about how those who wrote it saw their own leadership style, at those critical points in history. Leaders told him to dream big, give, and get to know different kinds of people. Bush counselled against sacrificing his soul for public approval. Gorbachev wrote poignantly about the fact that he would not be around by the time Charlie read his advice. 

There were also plenty of entries from sportsmen, authors and celebrities. J. K. Rowling advised Charlie not to take up smoking, and to read a lot. Carla Bruni told him to play with his dad every day: ‘car il à besoin de jouer, même s’il est un adulte’. Footballers David Beckham and Pelé and Olympians Steve Redgrave and Chris Hoy focused on the dogged persistence and hard work that had brought them such extraordinary success. Archbishop Desmond Tutu, Bill Clinton and the Dalai Lama urged him to give. 

Above all though, the advice was optimistic. The leaders who wrote in the book were genuinely excited about the world Charlie and his generation would inherit. 

The Sunday Times, Today Programme, BB5 live, and CNN have all covered the effort. Friends like Jared Cohen have adapted it. But until now I haven’t shared any of the content itself. So over the coming days we will upload here photos of the best advice from leaders to a future 14 year old. Most of it applies to the rest of us as well ...