The Australian played for the Brisbane Heat in the Women's Big Bash League four years ago, before returning to tennis ranked 683 in the world.
But she continued her incredible rise on Saturday by thrashing Czech teenager Marketa Vondrousova 6-1, 6-3 in the Roland Garros final to lift her maiden major trophy.
"No, not at all," she said of her hopes of winning a Grand Slam when she started her comeback.
"I think maybe in doubles, if I'm being completely honest. I think I was so close with Casey (Dellacqua) so many times. I felt maybe that was a possibility.
"But I think a new perspective in my life and in my career, it's brought this new belief, I suppose, and this feeling of belonging at the very top level.
"I feel like I'm playing some really good tennis. I know when I play my best tennis, I can match it against the world's best."
Barty lost in three Slam doubles finals alongside Dellacqua in 2013, but had only won two singles matches and lost nine at the big four tournaments when she stepped away five years ago.
She did not play another Grand Slam singles main-draw tie until 2017, and only reached the second week of a major for the first time at least year's US Open.
The 23-year-old said she does not think she could have seen such an upturn in her fortunes without taking a hiatus.
"Absolutely not. I don't even know if I'd be sitting here talking to you if I was playing tennis (and) if I didn't step away," Barty said.
"It's obviously a part of my life that I needed to deal with, and I feel like it was the best decision that I made at the time, and it was an even better one coming back."
Barty will rise to number two in the world when the updated rankings are released on Monday, behind only two-time Grand Slam champion Naomi Osaka.
She said she hopes a rivalry can blossom between the two, with Japanese star Osaka two years Barty's junior.
"I think we have only played a couple of times, but I'm sure that we'll play many more times over both of our careers, and hopefully they're in big matches."