"It didn't appeal to me. I was probably very tired that day," Dion said Monday about why she at first rejected the song.
The singer revisited the track and recorded a demo for it following advice from her late husband and former manager Rene Angelil.
"I sang the song once and they build the orchestra around it. I never re-sang it for the recording," she continued about creating the hit song.
"So the demo is the actual recording, but after that, I've sang it about three gazillion times," Dion said.
Dion was asked by a fan on the show about her love life following Angelil's death and if she is currently dating anyone.
"I don't date. I don't have a boyfriend and you know it doesn't mean that I will not find someone in my life. If I do that would be great, if I don't that would be great because I'm still in love," the 51-year-old said.
"I've been living all my life with Renee. He's still within me. I see him through the eyes of my children everyday," she continued.
Angelil died of throat cancer in January 2016 at the age of 73. The couple, who had been married since 1994, share three children, 18-year-old Rene-Charles and 9-year-old twins Nelson and Eddy.
Dion recently released her first English-language album in six years titled Courage.