"In the book I go into some of the mistakes I made, I've got no problem with that. But to say I was going in every day kicking chairs and all that -- who could work in that environment?
"Don't think for one minute I was going in every day behaving like a madman. People can be standoffish. There have been plenty of club jobs while I was off where I thought, 'I might get a call', but people talk in football. They didn't want to hear it, so I didn't get calls. That's why working with Martin was such a great opportunity for me to get back into the game. I was delighted to take it."
Keane is convinced that he has learned from his mistakes as a manager, which he chronicles in detail in the book.
"My man-management has to improve," Keane, 43, said. "It's about getting the balance right. I don't want people to be cosy with me. Do you think I was cosy with Brian Clough? Do you think I was cosy with Jack Charlton and Sir Alex Ferguson?
"I look back at my management and it wasn't as bad as some people say it was.
"I did okay at Sunderland. Okay it wasn't good enough at Ipswich, a few bad signings didn't help and moving on a goalscorer [Jordan Rhodes] didn't help, but it wasn't just down to my man-management skills.
"Go and ask the players who played 60 or 70 games for me and they'll say: 'Yeah, he was moody, but I enjoyed it.' I don't think I'll go into management and be a completely different person because players will see through that.
"I don't look at my management career and think: 'I'll go back in and be a completely different person.' Never, ever think players down-tooled for me.
"Yes, my recruitment was poor, I bought some bad players, particularly at Ipswich, but of all the teams I managed, I never, ever thought they weren't trying for me. There was always spirit there."
Five surprises
1. Keane quite likes Ferguson
Beyond the rows, bust-ups and barbs, Keane still has huge respect for the former Manchester United manager. For every criticism of Sir Alex Ferguson, there are several more compliments. Perhaps a truce could yet happen?
2. He is a health freak
A surprising revelation was how a meat-free diet during his "health-freakish phase" forced him to miss a game against Arsenal after his body ran out of iron. It emphasises his endless pursuit of (perceived) perfection.
3. He can do regret
Keane might not rue his challenge on Alfie Haaland but there are regrets aplenty, such as rejecting Real Madrid, hastening his exit from Manchester United and allowing himself to be referred to as "gaffer" by his players.
4. He likes groundsmen
The passage about his decision to allow the Sunderland groundsmen into the staff canteen, rather than have them "freezing to death while eating sandwiches in a hut", is an example of what many regard as the real Roy.
5. There could be a third book
At 43, Keane's career will surely develop from his current role as an assistant manager at Aston Villa and the Republic of Ireland. Having entitled this book The Second Half perhaps there will be a third called Fergie Time?
