Jeremy Warner: Ronson – Ernest's Alzheimer's was my idea

Outlook: Those who still wonder, as I have from time to time, about the origins of Ernest Saunders' Alzheimer's need look no further. The answer is contained in an autobiography published this week by the property developer Gerald Ronson, Leading From The Front.

Back in the early 1990s, Mr Ronson served time in Ford open prison along with Mr Saunders for his part in the Guinness affair. Mr Ronson recalls that despite the fact that he would gladly have strangled Mr Saunders for having ensnared him in the shares fraud, Mr Saunders was a regular visitor to his cell, where he would moan about this and that and the other, including how he couldn't possibly spend five years in prison and how he needed to get out.

This is such a choice anecdote that I make no excuses for repeating it in full. "I joked, 'Make out that you're mentally ill. It wouldn't be difficult for you because besides being a psychotic liar, you are mentally deranged ... If you made out you've got Alzheimer's, nobody could ever prove it, because if they looked inside your head, what are they going to find?' "

Mr Saunders replied that he liked the idea. When he left, Mr Ronson remarked to his cellmate: "I bet he'll do that, tricky bastard that he is."

In an appeal, the judge reduced Mr Saunders' sentence to two and a half years, after hearing evidence that Mr Saunders was suffering from pre-senile dementia. With parole, Mr Saunders qualified for almost immediate release, having served just 10 months. As soon as the former Guinness chairman was free, Mr Ronson recalls, "Saunders miraculously 'recovered', apparently the first person in medical history ever to do so."

Leading From The Front is the story of a remarkable life from one who has lived on the edge and come through intact. It's a rip-roaring read with important lessons for all those who take business seriously. "What you see is what you get," Mr Ronson says of himself. "What could be simpler than that?"