Football megastar David Beckham admits he made mistakes at Manchester United that led to a breakdown in relations with former manager Sir Alex Ferguson.
Beckham progressed from the youth ranks to become one of the biggest stars at Old Trafford, but was sold by Ferguson to Real Madrid in 2003.
Beckham accepts that his celebrity status and marriage to Spice Girl Victoria gave Ferguson cause to doubt his professionalism.
Speaking about his life and career on BBC Radio Four's Desert Island Discs, Beckham said: "At 41, I'd like to think that I'm more grown-up and a little wiser than when I was 21.
"There were certain decisions that I made back then that were wrong decisions and I can see why the manager got so frustrated by certain things."
Beckham and Ferguson's most public falling-out came in February 2003, when, after a defeat by Arsenal, Ferguson kicked a boot at Beckham that left him with a cut above the eye.
Beckham described it as a "freak accident", adding: "He could never do it again, because I have seen him in training."
But it was Ferguson who provided Beckham with much-needed reassurance following his sending-off during England's World Cup quarter-final loss to Argentina in 1998.
"The first person to call me after that game was Sir Alex Ferguson," said the former England captain. "He said, 'Son, get back to Manchester, you'll be fine' and that gave me strength to actually get through probably the toughest time I've been through in my life.
"My wife had told me we were expecting our first child, so it should have been a happy time and it wasn't. I look back at it and it was such a difficult time, not just for myself, because I knew once I was back in Manchester, I was protected.
"I had the support of the fans. Every single time I walked up to take a corner, the whole stadium stood up and clapped, and sang my name - I get emotional talking about it.
"But it was more difficult for my grandparents. They were being door-stepped by journalists, who were saying things I don't want my grandparents hearing about their grandson.
"The only thing I could do to protect my family was to say 'don't open the door to these people'."