Los Angeles, Nov 1 (IANS): Irish singer-songwriter and the frontman of the rock band 'U2', Paul David Hewson popularly known as 'Bono', published his memoir on Tuesday.

The book, titled 'Surrender: 40 Songs, One Story', doesn't just tell the story of 40 songs of 'U2' but also touches upon his love story with his wife Ali Hewson, reports 'CNN'.

Bono, who married Ali in 1982 and counts her as one of his closest friends, told the 'Sunday Times Magazine', "I also wrote the book to explain to my family what I was doing with their life because it was they who permissioned me to be away with U2 or lobbying Congress".

For him, the book is not just a memoir but beyond that, "Ali gave me the chance and covered for me at home. So I'm not writing a rock'n'roll memoir, (or) an activist's memoir, I'm not just writing a sojourner's memoir, I'm trying to write a love letter to my wife".

Bono calls the woman he shares four children with, "incredible."

"She's not just a mystery to me, by the way. She's a mystery to her daughters, to her sons," he said. "I mean, we're all trying to get to know her. She's endlessly fascinating. She's... full of mischief", he further mentioned, quoted by 'CNN'.

However, not that it's all been a bed of roses. According to Bono, the couple has weathered some tough times. "It's not like our love was absent of any dark undercurrents or briny water, [but] we got each other through those bits where it was hard to see where we were," he said.

"Ali calls it 'the work of love'. I wish she wouldn't use the word 'work' because I have a feeling there's an adjective, 'hard', that's inferred", he concluded.