Bono has revealed that he has a half-brother, whom he only learnt about when he himself was an adult.
Speaking to Lauren Laverne on BBC Radio's Desert Island Discs, the U2 frontman said he first found out about the man, who he describes as a brother he "loves and adores", in 2000.
He said his late father, Bob, had a "deep friendship" with a "gorgeous woman" and had a child with her, but that his own mother Iris, who died when Bono was 14, never knew.
Bono added that he had made peace with the situation.
"I asked him [his father] did he love my mother and he said yes, and I asked him how could this happen and he said, 'it can' and that he was trying to put it right, trying to do the right thing.
"He wasn't apologising, he was just stating these are the facts... I’m at peace with it."
Bono (62) also spoke to Laverne about how his relationship with his father came under tremendous strain following the death of his mother, although he now admits he was partly to blame, adding that after Bob's death in 2001, he apologised to him during a visit to a chapel in France.
"There was nobody there, I lit a candle and I got on my knees, and I just said, 'look, I’m sorry I wasn’t there for you, you went through a lot and please forgive me', and I felt free," Bono said.
Describing himself as "a work in progress", Bono said he grew up in a house with "three men shouting at each other" and has had some "anger management discussions" over the years.
In the wide-ranging interview, which will air on BBC Radio 4 on Sunday morning, Bono also spoke about a serious health scare he had in 2016 during which he said his chest was cut open during a long surgery.
He said the experience made him more vulnerable to music.
He also spoke about how his activism was sometimes difficult for the other members of U2 and it was difficult for them to see him in certain company, but added that they believed it was the right thing to do to get "certain things across the line".
Bono defended the band's decision to move some of their business activities to the Netherlands and discussed social media reaction to the verse about Ukraine he sent to Speaker of the United States House of Representatives Nancy Pelosi, which she read out at the White House last St Patrick’s Day, saying it was intended to be a Limerick, rather than a poem.
"It took 10 minutes, it was trying to be a satire, funny and the Speaker of The House, instead of saying Limerick, said it was poem and so people thought it was like Seamus Heaney!" Bono said.
Speaking about U2's future, the singer said what keeps the band together is unfinished business, and that they still haven't got to "that sound we hear in our heads".
Among the tracks Bono chose to take to a desert island were Show Me the Way by Peter Frampton, one of the first songs he sang with the other U2 band members in Mount Temple school in the late seventies, Emilie Sandé’s version of the hymn Abide with Me, and Ice Cream Sundae by Inhaler, whose lead singer is his son, Eli.
His desert island book was Ulysses because it would remind him of home and his "luxury item" was a guitar.
Desert Island Discs airs at 11.15am on BBC Radio 4 on Sunday.
Bono's autobiography, Surrender, will be published by Penguin Random House in November.