"And I’m alive and kicking, and I’m going to work," the actor, who wore a white T-shirt and a full beard, added. In his BBC interview, the 75-year-old revealed he lost his hair during his treatment and wanted his beard back "more than anything."
The "Tudors" actor said he is "very happy to be going back to work," explaining that, in a week, he’ll begin shooting a film called "Apples Never Fall" with Annette Benning.
"I just wish the headline wasn’t ‘that thing’ so much," Neill said, referring to cancer, "because the main thing is that I have written this book. It’s called ‘Did I Ever Tell You This?’ And it does mention cancer because that’s the sort of context in which I wrote it.
"But I didn’t really mean to write a book. I needed something to do while I was undergoing treatment, and I am used to going to work, and I suddenly couldn’t go to work. So that’s why I wrote the book, and I have to say there’s been great response to it. People seem to love it, which is great."
He added he was "nervous" about writing the book because he’s a first-time author but added that it was "fun" to reflect on his career, adding that the "tone of the book is one of surprise. I never thought that I would have a career as an actor, let alone an actor on screen.
"I am full of gratitude looking back on this life, and that’s what the book is about. And let’s not worry too much about ‘all that’ because I’m fine. OK!"
In his BBC interview, Neill had referred to the cancer as "ferocious" and said at the time he was diagnosed he thought he might be "dying."
During a press tour for "Jurassic World Dominion" last year, the actor noticed that glands in his neck did not feel right. After hearing his diagnosis from doctors, Neill said his response was pretty stoic, but it prompted him to "take stock of things," and he began writing his memoir to "distract" himself.
He joked that he suspected his publishers wanted him to "hurry" with the book in case he "kicked the bucket" before it was released.
He also reassured that while his book discusses his cancer, that's not what the book's about because he "can’t stand cancer books."
Per the Mayo Clinic, non-Hodgkin lymphoma is "a type of cancer that begins in your lymphatic system, which is part of the body's germ-fighting immune system. Advances in diagnosis and treatment of non-Hodgkin's lymphoma have helped improve the prognosis for people with this disease."
In an interview with The Guardian, the 75-year-old said he’s not afraid to die but would like to get in another couple decades of life if he can.
"We’ve built all these lovely terraces, we’ve got these olive trees and cypresses, and I want to be around to see it all mature," he said. "And I’ve got my lovely little grandchildren. I want to see them get big."
Fox News' Janelle Ash contributed to this report.