Since his youth in Dublin, Bono has hidden something from the world: his affection for the music of Abba. He just wasn't brave enough to announce it. Macho factors were involved, he confessed on a BBC Radio show; his peers were into punk at the time, not Swedish pop. Bono is secure enough now, per the Guardian, to say "they're just better songs. You can't be empirical about everything in art." Edge made a similar admission on the show. "We're big fans of this Scandinavian band," he said, "appreciators of their work in a way that grew over years."
Bono remembered young mothers in Dublin being Abba fans when he was young, per Yahoo Entertainment. "Certainly at closing time at our local pub, often young women would sing 'Thank You for the Music,'" he said, "and I would sing it and I was very thankful for the music." In discussing music they liked even though the musicians weren't always considered cool at the time, the bandmates also brought up the Bee Gees. The songs "Massachusetts" and "Tragedy" are "just crazy good," Bono said.
Also, "John Lennon owned up to loving the Bee Gees," he said, which might have added coolness. "We're fans of lots of great songwriters who aren't necessarily seen as very hip," the Edge said. But U2 once did Abba a disservice, Bono said, in butchering one of its hits with Benny Andersson onstage during a concert. Despite the effort, Bono thought, "This is not 'Dancing Queen.'" (Read more Bono stories.)