ABBA's Bjorn Ulvaeus and wife, music journalist Lena Kallersjo
58 year old Bjorn Ulvaeus' cannot remember the band's breakthrough performances in 1974 that propelled them to the status of a global pop super-group.
Even though the "Dancing Queen" act has sold 400 million records, Ulvaeus spends time looking at pictures and films of those old times trying to rekindle his memories.
As the London Telegraph reports, for him, it's as if he is experiencing the band's success for the first time - even though the band is now buffeted by a resurgence in popularity for the first time in years.
This is their most popular video on youtube...3.8 million plays; with a Brady Bunch' style split screen effect.