Michael Buble needed therapy to get over his split from Emily Blunt.
The Canadian singer was devastated when his engagement to the British actress ended in 2008 but he thinks the way he dealt with his "devastation" made the break-up the most important thing to happen to him.
He said: "When we were done I was devastated. I had to do therapy. I had to. I knew if I didn’t change I’d never be happy in my own skin.
"It was the worst thing that ever happened to me and the greatest thing. It ended through both of us being young and naïve and making silly mistakes. I did so many things out of insecurity."
Michael – whose wife Luisana Lopilato is pregnant with their first child – is no longer in contact with Emily because he thinks it would be "weird".
He said: "It would be weird for me to be in touch with her and her family as I have my own family now."