"Maurice’s death in 2003 and Robin’s last year had been a huge trauma for me and everyone in our family," he says. "Before that, in 1988, we’d lost our kid brother Andy, who had his own solo career, and my father, Hugh, died soon after.
"Robin’s much more recent passing had made me depressed, and there were times when I’d felt that nothing was worthwhile any more.
"But getting back to performing in Australia earlier this year - thanks to Linda giving me a metaphorical kicking - turned out to be the tonic I needed."
In addition to a feeling of isolation, Gibb says his grief was deepened by the fact he was not close to Robin for the last years of his life. "You see, it wasn’t just the loss of my brothers, it was the fact we didn’t really get on," he says. "And so I’ve lost all of my brothers without being friends with them.
"When Maurice passed, Robin and I just didn’t feel like the Bee Gees anymore, because the Bee Gees were the three of us.
"So while Robin went around saying 'I’ll always be a Bee Gee', he didn’t really want that: he wanted to be Robin Gibb, solo artist. Deep inside, I think that was so. That was the competition."
He compares the brothers’ estrangement to the relationship between Paul McCartney and John Lennon: "The fact that you couldn’t get over obstacles or issues in your life."
Most of all, he regrets not saying goodbye properly to any of his brothers.
"The only time I felt we made up was when I kissed Robin on the head the last time I saw him before he died," he says. "I didn’t get to see Andy before he died, and I never got to Maurice before he died. Mo died in two days, so that was very quick and a great shock to everyone."
Gibb was closest to youngest brother Andy, who he describes as being like a twin. Andy was a solo singer who died aged 30 from a heart condition. "Maurice and Robin were the real twins, but Andy and I were like twins, even though he was the youngest and I was the eldest. We sort of looked alike, and even had the same birthmark.
"We sang alike. We were very similar people. We were the only two that played tennis. Maurice and Robin didn’t play, but Andy and I would play just about every day.
He also believes Andy’s premature death contributed to the decline of their father’s health. "I lost my best friend when I lost Andy," he says. "And I believe the shock of losing him is what killed my father, because he went downhill and soon after died from a heart attack."
Although Gibb is relieved to have rediscovered his appetite for live performance again, he says he won’t participate in the organisation of Robin’s memorial service at St Paul’s Cathedral this year. Nor does he perform any songs sung by Robin, Maurice or Andy in his show. "I’ll only do the songs I was instrumental in creating or that we collaborated on together," he promises.
Gibbs’ Mythology Tour, supported by a ten-piece band, has been a huge success, including six nights in Australia.