The American tennis ace defeated Qinwen Zheng in three sets last weekend to win the prestigious season-ending title and explained that her hunger to end the year strongly was motivated by criticism of her poor results in the summer months.
Gauff said: "I remember after my loss in Cincinnati, they have the TV on Tennis Channel in the locker room.
"I couldn't hear what they were saying but the headline was like 'Gauff's Slump Summer' or something like that.
"I looked at that and I was just like, 'Dang, I have to turn it around somehow'. And then I lost a pretty tough match against Emma [Navarro] at the US Open. A lot of people were critiquing my season, you know, 'flop era.' I know all the Twitter terms.
"I think for me it was just motivation. I'm the author of my own story, and I'm not going to let anybody write me off."
The world number three has previously spoken about being fuelled to prove the doubters wrong by negativity but explained that she doesn't often speak to others about hurtful comments.
Gauff said: "I don't really talk to my team or anybody.
"Sometimes my boyfriend, but not to a deep extent. I do journal a lot, and I think it's just a lot of self-reflection and self-awareness. I do have a therapist. I haven't gone in a while, but I do that. I try to go once every two weeks, schedule permitting.
"I think a combination of her, myself and obviously my parents. My dad is pretty petty like me. I'm pretty sure the first thing he's going to say when I call him is something about what people were saying about me."