The 72-year-old music legend released his first and only official life story last month, and he has revealed he decided to publish the candid tome so that Elijah, six and Zachary, eight - whom he has with husband David Furnish - would have "the truth" before they start reading articles about their famous father when they are older.
Speaking in an interview with BBC Radio 2, he explained: "It was very painful but I wanted to write a book that my boys could read when they grow up that was the truth.
"My mother did some interviews, I didn't answer back because you can't answer back to the press because they always have the last word but I wanted, in this book, to rectify a few things, not settle scores but just to say what actually happened that they can read."
The 'I'm Still Standing' hitmaker had a troubled relationship with his mother Sheila - who died in 2017 - and also spent 16 years of his life battling a sex and drug addiction, which has been written about in many unofficial biographies, which Elton insisted are "not exactly accurate".
He added: "There's been a lot of books written about me, a lot of biographies, and they haven't had access to me so they're not exactly accurate.
"They're more about the music and stuff like that.
"This is the truth, and I can honestly say that nothing in this book is not true.
"I can swear that on my boy's lives.
"I just wanted them to have a record when I leave this mortal coil of how I actually was, what I went through and I want them to know that their dad was being honest and he made something of his life after a few hiccups along the way."
The 'Your Song' hitmaker announced he was retiring from touring in January last year, ending with his 'Farewell Yellow Brick Road' tour in 2020.
His decision came after the birth of his sons as he wants to spend the rest of his life surrounded by his children and David.
He said: "I'm used to it now but I don't like it so much now. "I find the hardest part of touring is the travelling.
"Getting on stage and playing is easy because I love it.
"It's the getting there and back that wears you out, and I travel in very luxurious way, but I've been travelling since I was 17, and the reason that I want to stop is, obviously, because I want to spend more time with David and the boys.
"The last part of my life I want to do something different, I don't want to keep going.
"Ten years ago, I would of said, 'Well yeah, I don't have any children, I just have David, I'll carry on like I am.'
"I had to rethink my life when we had kids and this is the result of it, this farewell tour."
- Bang! Showbiz