He told how, after the book was written but not yet published, he tried to engage his single-minded father (who'd said he wasn't interested in reading it) in a dialogue which might shed further light on the way their lives had unfolded. He asked Mike if he'd change anything. He was astonished when his father said he would.
Agassi had to stop his car and focus on the mobile phone. What would he change? "I wouldn't let you play tennis," came the reply. "You would have played baseball or golf."
Why, a gobsmacked Agassi asked? "You can play longer and win more money," said father. Agassi mock-dropped his head into his hands. The implication was plain - his father had learned nothing. However, Agassi also said that, if you could not develop the perspective that allowed you to understand other people's thoughts, wants and needs, you could at least be clear. "My father is nothing if not clear."
Just how clear was illustrated by Mike's rare appearance at one of his son's matches - one of his key meetings against great rival Pete Sampras. Mike, who preferred not to sit in a stand, was reluctantly ushered to a seat where his son saw his face watching him over Sampras's serving shoulder. Sampras was 15-40 down and preparing to send down a thunderbolt when a mobile phone fired off.
It rang and rang. Sampras went through his pre-serve routine again. Ready to serve. The phone went off again. Sampras halted. He swung round and said: "Sir, would you like to answer your phone?"
At the other end of the court, a horrified Agassi realised the culprit was his father.
Mike Agassi, instead of being embarrassed returned serve. "It's my phone. I'll answer it when I feel like it. Kiss my ass."
Sampras turned round to Agassi junior and mimed: "That's your dad!"
Indeed it was and, in the midst of all the personal insights, the bared soul and the soul-searching in Agassi's book and his remarks to the crowd at the Langham, it was clear that at least some of that single-mindedness and defiance would be needed to rise from 141 in the world to No1, as Agassi did in his ultimate phase of tennis self-determination.