The `Slumdog Millionaire` actress - who originally hails from the Indian city - visited the slums with a non-governmental organisation (NGO) recently, and was surprised to find no-one knew who she was.
She said: "People in the city recognise me as the girl from `Slumdog Millionaire`, and inevitably they stare. But when I visited the slums with an NGO, nobody recognised me at all. I didn`t mind."
However, the 26-year-old star admitted people often become confused when they meet her co-star Dev Patel - whom she began dating after meeting on the set of the Oscar-winning movie in 2008 - as they think he really did win millions on a game show, as his alter-ego Jamal Malik did in the film.
Freida added: "As for Dev, they hounded him, calling him crorepati, which means millionaire. Everyone needs entertainment, so I`m very glad the film reached them."
Despite her success, the actress confessed she has been known to stay in her pyjamas all day long when she is at her family home in Mumbai.
She told The Sunday Times magazine: "I generally used my time in Mumbai to unwind, so unless there`s anything important, I`ll be in my pyjamas the entire day, reading papers and watching movies."