The Kill Bill star told Style that she has always been surprised that she continues to get work in Hollywood.
Thurman said: "When I was 16, they were like, 'Mmm, well enjoy yourself. You might not be an adult woman actor'.
"And then when you're in your twenties, they're like, 'Enjoy yourself. That late-twenties thing thing is not going [to] work'. And somehow I hung around.
"Becoming a mother definitely took the focus off my work. Then I had a few panics that I couldn't get a job any more, and then I would get one."
The 39-year-old actress, who has two children, Maya Ray, 11 and Levon Roan, 8, from her marriage to Ethan Hawke, said that her passion for her work keeps her motivated.
She added: "I love what I do. For my wellbeing, I need to be reminded that I have other purposes. In the old days, people pined for their husbands. In modern life, your work is like your man, your love."