David Bowie only found out that his cancer was terminal 3 months before he died, according to a documentary that marked the anniversary of the superstar's death.
In the documentary, David Bowie: The Last Five Years, it was revealed that Bowie discovered his treatment was to be stopped while he was filming the music video for what would be his final single, Lazarus.
"David said: "˜I just want to make it a simple performance video'," said Johan Renck who directed the video, which features Bowie singing lines such as "Look up here, I'm in heaven" from a hospital bed.
Many believe that he came up with this idea after he got his prognosis, but he had come up with the plan for the video weeks before.
"I immediately said "˜the song is called Lazarus, you should be in the bed'," says Renck. "To me it had to do with the biblical aspect of it ... it had nothing to do with him being ill."
It wasn't until they were shooting the music video that he found out that they were ending the treatments and the illness would run it's course.
That didn't cause Bowie to lose hope though.
Continue to the next page to see what he did before he died.
Even with his grim diagnosis, Bowie had not given up hope of surviving his cancer and was still keen to make new work right up until the weeks before his death.
He had kept his illness a secret from the world, but paid homage to his death through his work.
He threw a lot of his energy into his final projects including Blackstar, his album and Lazarus, the New York City musical.
"Often he would go and record in the studio and then go and watch the rehearsals for Lazarus in the evening, or talk about the play in the morning, go to the studio, and then come back. It was quite an extraordinary workload," said Francis Whately, who came up with the new documentary.
Whately and Bowie had known each other for almost 20 year. They first met on the set of a short film they worked together on at the beginning of Whately's career. The pair regularly kept in touch over email.
"The David Bowie that I knew in my limited way was incredibly courteous, was incredibly polite, well informed, utterly charming. But I would question anyone who said they really knew him. I don't think anyone knew him," Whately said.
To outsiders, it didn't appear like his illness was slowing him down any.
"I think everyone would like me to say he was turning up to the studio to record Blackstar and he was terribly ill, but I don't think he was. There are musicians in the Blackstar band who didn't even know. We all now know he was ill, we know he was undergoing treatment, but it doesn't seem to have had an effect at all on his output," Whately said.
After his heart attack in 2003, Bowie bowed out of the public eye, something that he increasingly began to loathe over time. As much as he would have loved to move back to London, he stayed in New York for the relative anonymity it provided him.
"I don't find it strange he kept his illness so private," said Whately. "He'd had his life picked over for 40 years and he thought he had said everything he wanted to say, there was nothing more."
David Bowie died on January 10, 2016, just days after his 69th birthday and the release of his 25th studio album, Blackstar.
Bowie's death came as a shock to the world since he had only shared news of his illness with those closest to him.
"I still don't know if he started making Blackstar before he knew he was ill, or after," Whately said. "People are so desperate for Blackstar to be this parting gift that Bowie made for the world when he knew he was dying but I think it's simplistic to think that. There is more ambiguity there than people want to acknowledge. I don't think he knew he was going to die."
But you really never know.
"However, he must have known there was a chance he wasn't going to recover, so, to do an album with a certain amount of ambiguity in it, is Bowie playing the cat and mouse game that he always played."
Sources: The Guardian / Independent