Internationally-renowned novelist Sir Terry Pratchett has promoted assisted death as an option for Alzheimer's disease sufferers.
The fantasy writer has sold more than 70 million books worldwide and his Discworld series has become an international hit.
When he was diagnosed with Alzheimer's, he made it his mission to tell everyone.
"I was a journalist for a while and I believe in the truth. I have Alzheimer's. That's the truth and I would not lie about it.
"And I hope, and I have been told, that because I stood up and said 'I've got it' that has helped the cause of Alzheimer's in the UK," he told TVNZ's Close Up.
Pratchett suffers a rare form of early-onset Alzheimer's disease called posterior cortical atrophy (PCA). It leads areas at the back of the brain to slowly shrivel.
He added he was "neither proud of having it nor ashamed of having it" and that it could happen to anyone.
"You don't have to consort with naughty ladies to get it or anything like that," he said.
Pratchett's support of assisted death has drawn controversy in the UK, but he says there is no reason it should be illegal and does not believe it will mean that "old grannys are going to be marched into the gas chambers".
The term "assisted death" has also become a point of contention, with Pratchett saying those who label it "assisted suicide" are off the mark.
He said his time spent as a journalist led him to believe that suicide is an irrational act, but that assisted dying suggested an act that was undertaken using a lot more consideration.
Pratchett is currently working on a book called The Long Earth with science fiction writer Stephen Baxter.