Roger said he stopped believing that he could play because of injuries.
He had a third knee operation after not playing since Wimbledon.
He said the last three years have been difficult.
I knew I had been on thin ice for a long time.
There was a limit to what I was able to do. I stopped believing in it.
It was not what he was hoping for when he had a scanned a few months ago.
How do you announce, and when do you announce? When it becomes reality, this is when it happens. It wasn't bad, but it was a lot of work.
In a wide-ranging interview with Sally Nugent, Roger spoke about his emotional retirement statement, his trophy-laden career, looked at what's next for him and offered his recollections of the late Queen.
The eight-time Wimbledon champion announced his retirement last week.
"It's been an emotional few weeks to try to get them right, that they reflect how I'm feeling and thank all the people who have helped along the way," he stated.
I used to push my retirement thoughts away. It's not the way to go to work for me as a tennis player, so we'll deal with it when it comes. It did. I took care of it.
I think writing those words was a part of my rehabilitation.
Having achieved so much, he was happy to step away and now regarded as an all-time great.
During his time as world number one, he won 103 singles titles.
"I don't think people grow up and think they're going to win a lot," said the tennis player. You're happy if you win a Wimbledon title or become the best.
You don't think about how long the media and fans talk about breaking records.
I hope to be on a tour someday. It's a big deal to get into the top 100. We don't have a large base of players.
I over achieved in my thought processes. It has been a dream of mine for a long time. I'm happy to leave as well because I know that.
In an era when he, Nadal, Novak Djokovic, and Andy Murray were the dominant players in the major tournaments, he has played.
The four men are going to play in the same team at the Laver Cup, where Team Europe will play Team World.
In what will be the Swiss' final professional competition, Roger, Novak, Nadal, and Murray will line up for Europe along with two other players.
He believes that tennis fans don't have to worry about the sport's future now that it is over.
We didn't expect it at all. After Pete Sampras retired, we were more on a downward slope. So what's going to happen next? I came here and then he came. Both Novak and Andy were present.
"All of a sudden, there was this beautiful mix, we're all winning for 10 plus years, all the same tournaments, almost no one else could win anything else." It was a surety on the big tournaments.
I'm sure some fans will be sad I'm leaving, but there will always be wonderful new people.
The game is very safe and I'm sure it will see incredible new superstars.
He wants to stay in tennis and is interested in coaching the next generation of talent in Switzerland.
First, he wants to spend more time with his family.
He said that he tried to keep a clean slate when he retired because he had four children and needed his help. My wife has been by my side all the time. Let's look at what they want to do and what we should do.
I want to mentor the children and get a new Swiss star going. I can see those things if I help the federation a bit here and there.
I have to figure it out. I'll leave after this. After that, we have a vacation with the kids. It will be a good time to reflect and look ahead.
He wants to stay involved in some way in the game. I will not be a ghost or someone else.
The scenes on Monday during the state funeral of Queen Elizabeth II were very moving for the tennis player.
He remembered meeting the Queen on her last visit to Wimbledon in 2010 and praised the Royal Family for their support for tennis.
When she returned to Wimbledon after giving the trophy to Virginia Wade, she had the chance to eat lunch with me.
She came and everyone at the tennis was so happy that I met her. I will never forget that.