The Harry Potter author also said she loved getting rejection letters while writing her Cormoran Strike crime novels under her pseudonym Robert Galbraith, as it took her back to the earlier days of her career.
Rowling is one of the most high-profile writers of her generation thanks to her books and blockbuster film franchise about the boy wizard, as well the spin-off Fantastic Beasts films.
But she told Graham Norton on his BBC Radio 2 show: “I really do manage to lead a very unnoticed life which is just the way I like it.
“I think as a woman and not a particularly tall person, I blend in quite easily.”
She shared a story of a time she visited a cafe by the Smithfield market in London, one of the locations in her Strike books, and was miraculously missed by a member of the public who was looking for her.
She said: “My husband and I went there really early. I wanted to see what it was like, it was so atmospheric opposite the meat market and this man came in, in a high-vis jacket.
“He had just been unloading meat carcasses. And he said at the top of his voice, ‘someone told me JK Rowling was in here’ and he looked directly at me.
“And he then went, ‘I wouldn’t know what she looks like’ and walked out again.
“I just froze... we both just looked at each other and that was that.”
She also told Norton she used the male pen name for her contemporary crime novels about a unconventional private investigator because she “wanted not to be me”.
“I’d always wanted to write crime and I wanted to not do it with any fanfare,” she added.
“So I submitted the manuscript anonymously, and it was all great and I even enjoyed getting rejection letters again. It was fantastic, it was just like it used to be.”
She said she “did get away with it up to a point”, and she had wanted to get three of the books out “without being unmasked”.
“Because then I thought it would have a bit of momentum. I was a bit unlucky the way it happened.”
Rowling’s identity as the real writer of the novel was unveiled five years ago when a member of an entertainment law firm told his wife’s best friend, who then shared the news on Twitter.
She said she initially thought the leak was down to somebody at the BBC, as they had approached her about the book before they knew Robert Galbraith was really her.
Rowling’s fourth Strike book, Lethal White, was published last month.
The BBC has confirmed it will be made into a new TV series, following on from its previous adaptations of the first three novels.