The Harry Potter star said she gets mobbed by fans everywhere she goes, adding that she found university particularly difficult.
"If I went somewhere busy, I wouldn't last very long. I can't go to a museum, I'll last 10 or 15 minutes in a museum," she told the New York Times Style Magazine.
"The problem is that when one person asks for a photograph, then someone sees a flash goes off, then it's like a domino effect.
"Very quickly the situation starts to get out of control to a point where I can't manage it on my own."
Watson, who recently completed her third year at Oxford University, added: "My first two years at Brown weren't easy, not because I was bullied or because anyone gave me a particularly hard time.
"At Brown everyone does completely different things and very much chooses their own path, which is great, but it's also much more difficult, too. You're not with a group of people all the time at one time."
Her new film The Perks of Being a Wallflower opens on September 21 in US cinemas and October 3 in the UK.
Watch the Perks of Being a Wallflower trailer below: