His mother left him, his sister and his father when he was 15 months old. He and his sister bonded. His father married again. When a child was born, the sister broke off with the father, forcing him to choose between them. He loved his father. Then his father died.

Michael Grade tells all this, and of the consequent hurt to his psyche, not to a psychoanalyst, but to us, in his autobiography. Not since John Reith admitted to Malcolm Muggeridge his regrets at missing life's sweetness has any broadcasting executive revealed his inner self as Grade does here. But where Reith twitched the curtain, Grade has ripped it down. For that alone, the book deserves to be read.

It Seemed Like a Good Idea at the Time is a strange choice of title, as if what promised well has turned out badly. Perhaps he believes that, but it is hard to see why, particularly as, rightly so, he claims success in reinvigorating LWT, BBC1 and Channel 4. But pervading the book is a sense of potential not fulfilled, as if, by restlessness, he had never achieved as much as he might. If that is so, it is our loss. But he could have fooled me.

Grade is proud of his Jewishness and also sure he has met anti-semitism, reading Duke Hussey's description of him, when he left the BBC as 'an itinerant talent' as code for 'a wandering Jew'.

Grade is even prouder to be part of the wonderful Grade showbiz clan, Lew, Leslie and Bernie Delfont, agents and impresarios with a sure, popular touch. Yet he is upset if it is thought that that is all he is up to. He is a Grade, yet wants to be more than a Grade, as cultured - fluent French speaker, opera fan - as those whose patronising attitude he so resents.

The narrative introduces us to his formidable grandmother and, barely, to successive wives. We see his start as a sports reporter at the Daily Mirror, note his eye for a coming star, follow him as he takes up executive responsibilities at ITV and in Los Angeles. All this is readable enough.

What is riveting is his account of the great shoot-out at the BBC when, brought in to lead and cheer up BBC's TV programme-makers by repairing BBC1, and then moving on to take charge of all television, Grade is confronted by his old LWT friend John Birt, then deputy director-general, with special charges of News and Current Affairs. But Birt was determined to assert himself across the whole of the Corporation's output, and, according to Grade, to see off his only rival for director-generalship. Across the table, Birt's cold gaze confronts him. Grade blinks first and leaves.

He pitches up at Channel 4 where he confronts not Jeremy Isaacs, 'who threatened to throttle me if I betrayed a sacred trust' but an 'Isaacs cult' by which at every turn he was compared to his disadvantage with his predecessor. I could quibble apoplectically over a phrase or two in Grade's account of me and my legacy. But I will not. He is broadly fair, even handsomely so. In any case, this is his account, not mine.

Grade deserves huge credit for fighting and winning the political battle that, so far, has kept Channel 4 unprivatised. That has been his unique achievement. As to the range and quality of output, every chief executive has to believe he can do better than, and differently from, his predecessor. And every ex-chief executive detects a falling-off on the day of his departure. Grade, who significantly singles out for praise his director of programmes, John Willis, can be justly happy about his years in Horseferry Road. He did very well by his own lights. Who can do more?

It is early days, for an autobiography. Much lies ahead of Grade, including our verdict on the entertainment he will provide to millions at The Millennium Dome, and the shareholders' verdict on First Leisure under his chairmanship. But a new marriage marks a turning-point if not yet a conclusion.

More vulnerable than we knew, the irrepressible Michael Grade has written an unputdownable book.

Jeremy Isaacs was founding chief executive of Channel 4. He now runs his own production company