In 1991, I journeyed to England with Muhammad Ali to promote Muhammad Ali: His Life and Times, which had just been published in Great Britain. One afternoon, we were at a book signing in London when a woman in her forties passed through the line. She looked at Muhammad, then at me, and in a thick Irish accent asked, “Excuse me; are you Ali’s son?”

“No, ma’am,” I replied.

“Oh,” she said with obvious disappointment. “You look just like him.”

My initial reaction was to dismiss her as daft. After all, I’m white and was only four years younger than Muhammad. But then it occurred to me that this was one more example of how, when it came to Ali, people were colour-blind. And of course, it was a compliment of the highest order to be told that I looked just like Muhammad Ali.

There were also poignant moments on our tour. Late one afternoon, we were in Nottingham. It had been a long day for Muhammad. That morning in Leeds, he’d signed 900 books, posed for photographs, kissed babies, and shaken hands with literally thousands of admirers. Now that scene was being repeated with 500 more people who had waited in line for hours for their hero to arrive.

Ali was tired. He’d been awake since 5am, when he’d risen to pray and read from the Qur’an. His voice, already weak from the ravages of Parkinson’s Syndrome, was flagging. The facial “mask” which accompanied his medical condition was more pronounced than usual.

Most of the people in line were joyful. But one of them, a middle-aged woman with a kind face, wasn’t. Muhammad’s condition grieved her. As she approached him, she burst into tears.

Ali leaned over, kissed her on the cheek, and told her, “Don’t feel bad. God has blessed me. I’ve had a good life, and it’s still good. I’m having fun now.”

The woman walked away smiling.

I met Ali for the first time in March 1967, I was a student at Columbia University and the host of a radio show called Personalities In Sports that aired weekly on the student-run radio station. Muhammad was preparing to fight Zora Folley at Madison Square Garden and I had been granted an interview with him. For an 18-year-old sports fan, it was heady stuff.

At that point in Ali’s career, he was virtually unbeatable. Ali-Folley would be his seventh championship defence in less than a year and his final bout before a three-and-a-half-year exile from boxing. The war in Vietnam was at its peak. The National Selective Service Presidential Appeal Board had voted unanimously to maintain Muhammad’s eligibility for the military draft, and he’d been ordered to report for induction in April. The assumption was that he would refuse induction. Ali himself had hinted as much when he said, “Why should they ask me to put on a uniform and go 10,000 miles from home and drop bombs and bullets on brown people in Vietnam, while so-called Negro people in Louisville are treated like dogs?”

At Madison Square Garden, I watched Ali go through a series of exercises. Then I stood at the edge of the ring as he sparred with Jimmy Ellis. When that was done, he went into his dressing room and I followed. I wasn’t from the New York Times or any other news organisation of note, but that didn’t seem to matter. Ali told me to turn on my tape recorder. We talked mostly about Nation of Islam doctrine, with some questions about the military draft, Folley, and boxing in general thrown in. Ten minutes after we began, Ali announced, “That’s all I’m gonna do,” and the interview was over.

My personal relationship with Ali began in 1988, when we met in New York to explore the possibility of my writing the book that ultimately became Muhammad Ali: His Life and Times. There was a threshold issue I had to confront. Like millions of admirers, I’d seen Muhammad on television. Sometimes he’d looked well. Other times, the light seemed all but gone from his eyes. I didn’t want to involve myself with the project unless Muhammad was capable of making a significant contribution to it. And I didn’t want to spend several years working on a book that would be a source of depression rather than joy.

Other than JFK, my boyhood hero, I don’t think there’s a person on the planet who would have affected me in that manner

To resolve those issues, after meeting initially with Muhammad and his wife, Lonnie Ali, I accepted their invitation to spend five days at their home in Berrien Springs, Michigan. My first day there, I was intimidated by Ali’s presence. I found it hard to make eye contact with him. Other than John F Kennedy, who was my boyhood hero, I don’t think there’s a person on the planet who would have affected me in that manner; certainly not to that extent. Then, on the second morning, I went downstairs to the kitchen. Muhammad was sitting at the breakfast table, finishing his cereal and toast. He looked up and asked if I wanted cornflakes or granola. And in that moment, I realised that any distance between us was my fault. Muhammad didn’t want to be put on a pedestal. He wanted me to relate to him the same way I’d relate to anyone else.

In researching Ali’s life, I proceeded on several levels. First, there were Muhammad’s personal papers, medical records, cartons of legal and financial documents, newspapers, magazines, and tapes. Next, I interviewed approximately two hundred people who’d known Ali over the years: members of his family, friends, ring opponents, business associates, doctors, world leaders, and others. Unlike Ali’s earlier biographers, I enjoyed total access to virtually all of the key players in his life. My questions were answered with candour by almost everyone. And there were countless days spent with Muhammad. I travelled with him around the world, spent weeks in his home, and entertained him in mine.

Inevitably, writing the book involved revisiting my own youth. It led me to recall watching the 1960 Olympics on television and reading newspapers in high school for reports of Cassius Clay’s early fights. I reexperienced listening to the radio as a 17-year-old college freshman the night Clay beat Sonny Liston for the heavyweight championship. The war in Vietnam, assassinations, riots in America’s inner cities; in one way or another, so many of the key events in American history that I remembered were intertwined with Ali’s life. And I relived sitting in a New York theatre on 2 October 1980, turning my face away from the screen to avoid watching the brutalisation of an aging Ali at the hands of Larry Holmes.

When I began working with Muhammad, I came to realise that, despite his speech difficulties, he had no intellectual deficits. At that time in his life, his wit was sharp and his thought processes were clear. He didn’t feel sorry for himself because of his physical condition, and there was no reason for anyone else to feel sorry for him. He loved being Muhammad Ali and was as happy with each day as anybody I knew.

Facebook Twitter Pinterest Muhammad Ali was deeply spiritual but never sought to to impose his religious beliefs on other people. Photograph: Getty Images

Ali was a towering social and political figure. He stood as a beacon of hope for oppressed people around the world and an embodiment of the principle that, unless you have a very good reason for killing people, war is wrong. In some ways, he was a very simple man. In others, he was quite complex. But first and foremost, in the years that I knew him, Muhammad was deeply religious and spiritual. I don’t think I’ve met anybody ever who was more sincere about his religious principles than Muhammad was. At the end of each day, Ali asked himself, “If God were to judge me based just on what I did today, would I go to heaven or hell?”

“I’m not afraid of dying,” Muhammad told me. “I have faith; I do everything I can to live my life right; and I believe that dying will bring me closer to God.”

Yet Ali never sought to impose his religious beliefs on other people. Indeed, once when I accompanied him to services at a mosque to share that part of his life, he told me, “When we say our Islamic prayers, you can say your Jewish prayers. Only don’t say them out loud because it might offend someone.”

I also recall another moment between us that turned on Muhammad’s religious beliefs. One day, we were discussing Ali’s 1976 ‘autobiography’. The book contains numerous allegorical tales, including the claim that young Cassius Clay threw his Olympic gold medal into the Ohio River after being denied service at a segregated restaurant.

“You didn’t really do that, did you?” I queried.

“Yes, I did.”

“Swear to Allah.”

There was no response.

“Swear to Allah,” I pressed.

“Someone stole it,” Ali admitted. “Or I lost it.”

Muhammad Ali: fighter, joker, magician, religious disciple, preacher Read more

Another memory I have of that time is of waking up one morning in Ali’s home and hearing Lonnie cry out, “Oh my God! Muhammad! What have you done?”

Naturally, I was curious. So I put on my clothes, went downstairs, and found Lonnie standing in the living room amidst piles of clothes, boxes, and other belongings. Apparently, during the night, Muhammad had been unable to sleep. As he often does under those circumstances, he’d gone downstairs to read the Qur’an. Then, for reasons known only to him, he’d grown curious as to what was in the closets. And the easiest way to satisfy that curiosity was to empty all of them out on to the living room floor. Suffice it to say that Lonnie assumed it was Muhammad (and not me) who had done the deed.

There are so many memories I have of Ali that conjure up a smile. Once, when Muhammad and I got in his car to do some errands, he told me, “You get in back; I’ll drive; and it will be like Driving Miss Daisy.”

On another occasion, when Ali and Lonnie were coming to my apartment for dinner, I invited one of his favourite rock stars – Chubby Checker, who lived in Philadelphia – to join us. Chubby drove 90 miles to New York. When Ali saw him, he started jumping up and down, shouting, “It’s Chubby Checker! It’s Chubby Checker!” But what touched me most about that evening was an exchange that came after dinner. We were sitting in the living room. Muhammad looked at Chubby and asked, “Did you drive all the way from Philadelphia just to see me?” Chubby said yes. And Ali responded, shaking his head, “I can’t believe it. I’m honoured.”

I researched and wrote Muhammad Ali: His Life And Times for two years. Finally, in September 1990, I journeyed again to Berrien Springs to meet with Muhammad, Lonnie, and Howard Bingham (Ali’s closest friend). For eight days, we read every word of the manuscript aloud. By agreement, there would be no censorship. The purpose of our reading was to ensure that the book was factually accurate.

At one point during our reading, Lonnie quoted some thoughts from Alex Wallau, who’d been a producer for ABC Sports and later became president of the network. Wallau had expressed the view that, even if Ali had foreknowledge of how boxing would affect his physical condition, “If he had it to do all over, he’d live his life the same way. He’d still choose to be a fighter.”

As soon as Lonnie read those words, Muhammad sat up straight in his chair and said, “You bet I would.”

Muhammad Ali: share your photos and tributes with us Read more

The reading also included some particularly harsh words from Joe Frazier. “I hated Ali,” Joe said. “God might not like me talking that way, but it’s in my heart. Twenty years, I’ve been fighting Ali, and I still want to take him apart piece by piece and send him back to Jesus.”

Facebook Twitter Pinterest Muhammad Ali taunts Joe Frazier before their fight in 1971. The two boxers never saw eye to eye but did soften toward one another in later years. Photograph: Getty Images

Then the words got harsher. “He shook me in Manila,” Joe acknowledged. “He won. But I sent him home worse than he came. Look at him now. He’s damaged goods. I know it; you know it. Everyone knows it; they just don’t want to say. He was always making fun of me. I’m the dummy. I’m the one getting hit in the head. Tell me now. Him or me; which one talks worse now? He can’t talk no more and he still tries to make noise.”

There was a silent moment.

“Did you hear that, Muhammad?” Lonnie asked.

Ali nodded.

“How do you feel, knowing that hundreds of thousands of people will read that?”

The unseen Muhammad Ali: prize fighter ... and family man – in pictures Read more

“It’s what he said,” Ali answered.

During the time I spent with Muhammad, he was constantly creating new memories and generating “new material”.

We were in Seattle once to attend a dinner where Ali was honoured as “The Fighter of the Century.” The festivities included a fight card at The Kingdome. Meeting Muhammad, the undercard fighters were in awe. One of them, a lightweight with a losing record in a handful of professional bouts, went so far as to confess, “Mr Ali, I just want you to know; when I’m going to the ring for a fight, I get real nervous. So I say to myself, ‘I’m Muhammad Ali. I’m the greatest fighter of all time, and no one can beat me.’”

Ali leaned toward the fighter and whispered, “When I was boxing and got nervous before a fight, I said the same thing.”

“If you do roadwork in the snow, it makes you tough,” another young fighter told Muhammad.

“If you do roadwork in the snow, it makes you sick,” Ali countered.

Another time, I watched as Ali stopped to shake hands with an elderly white man who had a deep Southern accent.

“How old are you?” Muhammad queried.

“Eighty-one.”

“Where are you from?”

“Mississippi.”

“Did you ever call anyone a nigger?”

“Oh, no. Not me.”

After the man left, Muhammad turned to me, laughing. “Do you believe that? An 81-year-old white man from Mississippi; never called anyone a nigger.”

Shortly thereafter, we attended a tribute to Muhammad at the Smithsonian Institution in Washington D.C. I made some opening remarks and referred to an incident that had occurred years earlier when Ali took a flight from Washington to New York. As the flight crew readied for take-off, an attendant instructed, “Mr Ali; please buckle your seatbelt.”

“Superman don’t need no seatbelt,” Ali informed her.

Muhammad Ali's best quotes: 'Float like a butterfly, sting like a bee' Read more

“Mr Ali,” the flight attendant said sweetly. “Superman don’t need no plane.”

When I retold that story, Muhammad’s face lit up and he laughed as hard as anyone in the audience.

Ali’s ability to laugh at himself also surfaced when we authorised Easton Press to publish 3,500 copies of a leather-bound edition of Muhammad Ali: His Life And Times. Pursuant to contract, we each agreed to sign 3,500 signature pages for insertion in the book. I was to receive $3 per signature; Ali considerably more.

“This is fantastic,” I told myself. “If I do 10 signatures a minute, that’s 600 signatures an hour… Divide 3,500 by 600 … Wow! I’ll get $10,500 for six hours’ work.”

Except when I started signing, I found that I couldn’t sign more than a few hundred pages at a time. “Any more than that,” I confided in Muhammad, “and I can’t connect the letters properly. Something starts misfiring in my brain.”

“Now you know,” Ali told me, referring to his own physical condition. “It wasn’t boxing. It was the autographs.”

Muhammad Ali never felt sorry for himself, even as his physical condition worsened. Photograph: Dave Thompson/PA

Spending time together also rekindled memories for Muhammad. In 1996, we were on a media bus in Atlanta. Several video monitors were showing a tape of Cassius Clay’s antics prior to his first fight against Sonny Liston.

“It’s sad Sonny Liston is dead,” Muhammad told me. “I’d like to be able to sit down with him. Two old men, just sitting around, talking about old times.”

“What would you say to him?”

Ali’s eyes grew wide. “I’d tell him, ‘Man, you scared me.’”

Then ‘The Rumble in the Jungle’ came on the screen, and Ali grew wistful.

“So many people come up to me and tell me they remember where they were when I whupped George Foreman. I remember where I was too.”

It was in a boxing ring, of course, that Ali first inserted himself into the consciousness of the British people. The seminal moment came at two minutes and 55 seconds of the fourth round of his 18 June 1963 fight against Henry Cooper. That was when ‘Enery’s Hammer landed flush on Cassius Marcellus Clay Jr’s jaw. Cassius fell to the canvas like he’d been shot. Only the bell enabled him to survive. Between rounds, trainer Angelo Dundee revived his fighter. Clay stopped Cooper on cuts in the following round. Three years later, he duplicated that feat as Muhammad Ali.

I mention that moment now in a stream of consciousness that connects to the day years ago that Muhammed telephoned to wish me a Merry Christmas. “Think about it,” I suggested. “A Muslim calling a Jew to wish him well on a Christian holiday. There’s a message in that for anyone who’s listening.”

Henry Cooper tries to land a punch on Ali (then Cassius Clay) at Wembley Stadium in 1963. Photograph: Daily Sketch/Rex

“We’re all trying to get to the same place,” Muhammad told me.

I’d like to think that Muhammad Ali and Henry Cooper are in the same place now. It has been suggested that Sir Henry’s skin might cut less easily in Heaven and that he and Ali are readying for a third bout. If so, I suspect that each man is looking forward to the challenge.