Imagine waiting to do a job since you were aged three.
And now you’re in your 69th year, and you’re still waiting.
We take it for granted that the Prince of Wales is the heir to the throne – and has been since he was a child.
But in reality, that’s an awfully long time in which to prepare to be the next Monarch – whilst attempting to carve out a role for yourself.
Prince Charles has been the heir presumptive for 65 years.
In many ways, being the actual Head of State is much easier.
By easy, I mean it’s more straightforward: there are the formalities of weekly meetings with the Prime Minister, welcoming other Heads of State, turning Bills into Acts of Parliament and slotting state occasions into your annual calendar.
But what if you know that, by your birth, the top job is coming your way at some point in the future – but not for many, many years.
This was the dilemma facing Prince Charles when, as a young man, he left the military and was forced to work out what he was going to do and how he was going to spend the bulk of his adult life.
Over the last few days, I’ve watched the Prince of Wales up close.
Others have done royal tours like this - many times before.
But for me, it was a first time on tour with the Prince – and in later days with the Duchess of Cornwall as well.
The Prince of Wales has just spent two days in Romania and, together, the couple are part way through their five day tour of Italy.
What struck me was how the Prince’s personality is at odds with his public perception.
I didn’t see a stiff, out of touch Prince to whom people cannot relate.
I watched a man who charmed everyone he met: from the youngest to the oldest; from senior members of the clergy to children in a hospice with terminal illness; from crowds of international tourists in Florence to a group of Romanian folk dancers in Bucharest.
In short, I found someone who is very comfortable in his own skin and a man at ease with others - no matter what walk of life they are from.
Not then, the aloof royal who is socially awkward and has a well known habit for talking to plants.
Although he does talk - of sorts - to trees.
When he helped to plant a sapling at nature reserve in Bucharest, Prince Charles gently shook the tree afterwards and said: “Good luck tree!”
It was just as the photographer standing next to me said he would moments before it happened (Tim, the man with the camera, has heard it many times before).
Should we worry the next King talks to plants?
I could think of many worse attributes.
But the tree-planting and the other parts of his programme here, leaves Prince Charles open to the charge that he was simply indulging in his own passions: visiting an urban nature reserve, restoring traditional buildings, conserving rural ways of life and promoting tolerance of different religions.
As one of his team said to me as we stood chatting in an airport departure lounge, he is a man motivated entirely by compassion.
So his interest in conservation and the environment developed from a compassion for wildlife and a concern for how ecosystems impact on the wellbeing of us all.
His mission to restore old buildings, this official told me, stems from a compassion for the built environment in which people live and work.
And his desire to build the Princes Trust grew from his compassion for those who never had the privileges he enjoyed.
When he left the Navy in 1977 (he used his military pension to start the charity) he wanted to help the most disadvantaged – despite being told he shouldn’t stick his nose into areas where it wasn’t welcome.
The disturbing riots of the early 1980s in Toxteth in Liverpool and in Brixton in London made him all the more determined The Princes Trust should succeed.
The Prince has also launched a foundation which carries his name in Romania.
And those being helped by that charity don't think the Prince was selfishly promoting his own interests – they say his visits and his time do make a difference, do get things done, do change people’s lives.
And from what I saw of the Duchess of Cornwall’s visit to a former mafia villa in Naples – where they now care for children with challenging mental conditions and also give support to those whose loved ones were innocent victims of mafia murder – they will give you much the same response: the visit, the publicity and the attention do make a difference.
Now, we could – and should - talk about the mistakes Prince Charles and those around him made over Diana, Princess of Wales.
Most observers do now conclude it was a marriage that should never have happened and there are many people in many places (the Prince, the Duchess of Cornwall and Diana included) who share the blame for that.
And we shall discuss Diana many more times this summer, in this 20th year since her sudden death in Paris.
So will King Charles III (as we assume he will be called) be a different Monarch to his mother?
Of course he will.
She has spent a lifetime concealing her thoughts and feelings.
He, however, has not.
And given the Prince of Wales is approaching his 70s, it’s safe to assume he is not going to change his mind about the issues on which he’s been campaigning so publicly for so many years.
But, when the time comes, he won’t be able to be a ‘campaigning King’.
The constitutional role he will inherit does not allow it.
Yes, he’ll have a weekly private audience with the Prime Minster of the day – just as the Queen has had with a dozen or so prime ministers to date (and even the Queen can talk candidly in those).
But caring and campaigning, as we have grown used to him doing, cannot – and must not - be confused with meddling and interfering.
The Royal Family must operate separately from – and independently of – government and most people would assume that those rules also apply to the writing of long letters to ministers – like those which were nicknamed the ‘Spider Letters’ after Charles’ handwriting.
But in much the same way as Charles and Camilla have done on this tour of three EU countries, the King will be able to project UK diplomacy into areas which are simply beyond the reach of politicians.
It’s actually the reason why the Foreign Office has dispatched the royals into Europe - to coincide with the Prime Minister firing off the Article 50 letter to kick start Brexit.
Charles and Camila are doing Romania, Italy and Austria. Prince William and Kate have already been to France and will be in Germany and Poland in the summer.
And from the reception William and Kate received in Paris last month – and Charles and Camilla have received in Romania and Italy – you might argue that the soft power (as diplomats like to call it) deployed by the royals is working very well for the UK right now (although I’d argue its success or otherwise is very hard to measure).
But when I think of the lines of Romanian television cameras for the Prince in Bucharest and the mad scramble for pictures of the Duchess in Naples (which resulted in me missing my car ride back to the airport) they are already projecting a different kind of British message into these countries to the message being projected by Brexit.
Of course, to be a successful King or Queen, you have to have the support of the people.
Prince Charles’ mother has it (in spades right now).
But he doesn’t (not even close to the levels enjoyed by The Queen).
That would a problem were his public perception to remain unchanged.
But with the Queen doing less and less and the ‘King-in-waiting doing more and more, he does have an opportunity to shape – and to change - his public image.
The rehabilitation of the Prince of Wales since the years after the death of Diana has been a long and a slow one.
Charles has made a lot of progress.
But it’s not yet complete.
As King he will have to ensure more than ever that his priorities are also his people’s priorities.
And that is the challenge for him – and those around him – as the transition from one Monarch to the next inches slowly forward.