The 70-year-old keyboardist and singer quit the band in 1998, and Stevie Nicks once said there was "more of a chance of an astroid hitting Earth" than of McVie rejoining Fleetwood Mac.
"It was never anything personal between the five of us," McVie says of her departure. The singer had bought a house in England at the time, and "had some deluded idea that I wanted to live the 'Country Lady' life... a normal, domestic life with roots."
McVie subsequently went through a divorce with husband Eddy Quintela, and says the isolation of country life made her "quite ill and depressed." The musician "gravitated back to the piano" as a means of expression and "started diddling around."
"I don't think talent or the gift ever goes away," she says of her music. "I just think that it had got so buried."
"I started to think, 'What am I doing? I really miss that camaraderie with [Fleetwood Mac]. I miss everything about it,'" McVie recalls. "I missed the music, to be able to create again. I couldn't imagine doing it with anyone besides Fleetwood Mac. I knew that they were my musical family."
The reunion tour, On With the Show, will kick off with McVie in Minneapolis on September 30. Fleetwood Mac is slated to perform thirty-four shows in thirty-three North American cities, and tickets go on sale April 7.
"Then we just have to see what will happen after that," McVie says. The band had spent time working on songs prior to McVie's return, but won't release any new music until after the tour.
2014: The Year in Music [PHOTOS]