ABBA songs are so anthemic, and so ingrained in your system, that you can't really remember when you heard them.

I didn't realise how many Abba songs I knew. But I knew them all. Every single one of them.

It's lovely to be told, 'Your music has given me so much happiness in my life.' Who wouldn't want to hear that?

Abba songs, as anyone who knows knows, are constructed, technically and harmonically, so as to physically imprint the human brain as if biting it with acid, to ensure we will never, ever, ever, be able to forget them.

We have influenced other writers obviously," says Ulvaeus. "With such a string of hits you are bound to influence other people.

Before the Beatles, songwriters were very anonymous people, and nobody paid any attention to them.

Well mostly in song writing my experience is that there isn't so much inspiration as hard work. You sit there for hours, days and weeks with a guitar and piano until something good comes.

What you make up in your heads sticks if it's good, falls out if it's bad. If we still remember something a day after we made it up, it might be worth building on.

We simply write the kind of music we enjoy most and hope that our audience will enjoy it too.

It's so humbling and I'm grateful but I cannot say I understand quite how that happened. It's kind of a miracle, never in our wildest dreams did we think that these songs that we wrote would last for such a long time.

There’s a real melancholy in [Abba’s] songs… all the flourishes, like big double octaves on the piano. We stole them like crazy.

We don't want to write political songs. We don't want to turn our records into speeches.

I had a dream and it was fulfilled by meeting with Benny, Bjorn and Agnetha.

I can spot empty flattery and know exactly where I stand. In the end it's really only my own approval or disapproval that means anything.