His words have brought immense joy to millions of children around the world, but arguably Roald Dahl's most important piece of writing is one that is devastating in its sadness.
It is his account of the day in 1962 when he was robbed of a child.
"Olivia, my eldest daughter, caught measles when she was seven years old. As the illness took its usual course I can remember reading to her often in bed and not feeling particularly alarmed about it.
"Then one morning, when she was well on the road to recovery, I was sitting on her bed showing her how to fashion little animals out of coloured pipe-cleaners, and when it came to her turn to make one herself, I noticed that her fingers and her mind were not working together and she couldn't do anything. 'Are you feeling all right?' I asked her. 'I feel all sleepy,' she said. In an hour, she was unconscious. In twelve hours she was dead."
Those parents who refuse to vaccinate themselves or their children, likely haven't seen or experienced the pain caused by vaccine-preventable illness. Dahl did.
"It is not yet accepted that measles can be a dangerous illness. Believe me, it is. In my opinion parents who now refuse to have their children immunised are putting the lives of those children at risk."
And yet, still, parents refuse to do so.
To ignore the overwhelming advantages of vaccines in favour of a person's natural immunity is to indulge in idiocy.
Those peddling misinformation and mistruths about vaccines are a danger to society.
It's like driving on the same roads as people who refuse to pay attention to stop signs.
It is irresponsible, selfish and outright dangerous. It ignores basic science. Hell, it ignores basic math.
The chances of serious injury or even death from the MMR (measles, mumps, rubella) vaccine are miniscule - the odds are in the millions. Measles has a 10 percent chance of hospitalisation. Measles encephalitis, as Olivia had, happens in 1 in 1000 cases. Measles causes death in 1-2 of every 1000 cases.
As Dahl writes: "it really is almost a crime to allow your child to go unimmunised".
Measles has never been eradicated in New Zealand, unlike in other Western countries. Herd immunity, the ability of a population to protect itself, requires 95 percent of the population to be vaccinated. While New Zealand's overall rate is getting close to 95 percent, importantly, there are large pockets that fall well below that, including amongst teenagers and young adults.
On the West Coast, for example, the vaccination rate is 81 percent. Should measles take hold, it would sweep the population.
This is serious -- and it's happening now. Already, the latest outbreak has spread to five regions, and closed three schools. Almost a quarter of cases in Waikato have required hospitalisation.
The MMR shot doesn't provide 100 percent protection from measles, but, if you've had the correct shots, you'll likely be fine. If you were born in the years before 1969, when measles was rampant, you'll have natural immunity, so you'll also be fine.
The same can't be said for newborn babies, those undergoing chemotherapy, or those whose immune systems are compromised.
They are at huge risk. But, so are teenagers and young adults -- otherwise fit and healthy individuals.
Measles is more contagious than the common cold, the flu and Ebola.
Fatalities do happen -- in 1991, seven New Zealanders died.
I've made this argument before. I know that I'll once again be criticised by anti-vaxxers for pointing out the idiocy of their position. I don't care. These people are dangerous idiots.
They live in a fantasy world of twisted arguments, and irrelevant anecdotes.
Roald Dahl, master of fantasy and fiction, knew this. And he knew that it would be obscene to allow others to suffer, in the same way his daughter had.
"Incidentally, I dedicated two of my books to Olivia, the first was James and the Giant Peach. That was when she was still alive. The second was The BFG, dedicated to her memory after she had died from measles. You will see her name at the beginning of each of these books. And I know how happy she would be if only she could know that her death had helped to save a good deal of illness and death among other children."
To read Road Dahl's full entry, click here.