Kate Winslet has said she was unable to enjoy the success of Titanic because it was such a "frantic" time.
The actress said the 1997 film, which won 11 Oscars, changed her life "overnight" - an "overwhelming" change for which she was not prepared.
Winslet, 40, starred in the blockbuster hit alongside Leonardo DiCaprio, with the two stars playing Jack and Rose - a couple who find love on the ill-fated liner.
Speaking at a Bafta event called A Life In Pictures, in central London, Winslet told the audience: "It was a huge moment of course in my life. It was a big turning point moment. And my life did change really overnight.
"And I remember people saying to me before the film came out, 'How are you going to cope? Your life is going to be ... how are you going to not change?'.
"And I would feel almost defensive and angry and think, 'Well of course I'm not going to change. I'm not going to change, what are you talking about? My life's not going to change'.
"And it truly did, overnight. I remember one day being able to go and buy a newspaper and a pint of milk, no problem, and the next day I actually couldn't get out of the house because of paparazzi. And that was a huge shock.
"And nothing really prepares you for that. No one really can tell you about what to expect because it's so sort of unknowable. And so weird."
Winslet said that "luckily" her life was not like that at all any more and it felt like she was in a minority back then.
"At the time I think there were very few suddenly famous young women of my age range. I think there are a lot more now and it's much more sort of spread out," she said.
Winslet described it as "pretty overwhelming", adding: "I can honestly say I wasn't able to even really enjoy the success of Titanic because it was so frantic. I just thought, 'Well I'll just throw myself into work and concentrate and just do the work and make sure I'm following my instincts and that I must hang on to.
"I remember really somehow knowing that that was the right thing to do as opposed to doing lots more big things."
Winslet said she loved the script, the part and the love story between Jack and Rose.
"And of course Leonardo DiCaprio's name had been mentioned as a possible Jack. And I actually read with some very well-known actors for that role which was amazing and great fun but I just kept thinking, 'Oh God I really hope he does it, I really hope Leo does it'.
"And lucky for me he did. And it was a completely extraordinary experience but very, very hard. Really very hard."
When filming finished she said she remembered falling asleep one afternoon at about 4.30pm and waking up the following morning at 11am. "I was absolutely shattered," she said.
Winslet also told the Bafta event that "being a Brit" means she thinks it is "vulgar" to discuss how much she gets paid.
She clarified her stance on the gender pay gap debate and criticised the questions asked about the issue by journalists on red carpets.
Actresses such as Jennifer Lawrence, Meryl Streep and Sharon Stone have spoken out on the subject b ut Winslet has previously said that conversations surrounding the inequality were "uncomfortable and vulgar".
She said tonight: "The gender pay gap thing. Jennifer Lawrence is amazing for speaking up and I think that anyone in this industry, particularly women, if there's something strongly that they feel isn't working for them or if they're being discriminated against in any way, shape or form, it's very, very important to speak up and so I fully applaud that.
"What I have a problem with is that there's a separate thing that has started happening is that the lid has been somewhat lifted for journalists, and so journalists on red carpets will now say, 'So how do you feel about the gender pay gap?'.
"'What? What's the specific question?'. 'Well, do you know that you got paid less or more than Michael Fassbender?'.
"That question? That to me is not very nice. I'm not going to have that conversation with a friend or even a family member, let alone in public.
"And so what's happened as a result of these big very important discussions is that we're then subjected to a particular line of questioning that being a Brit strikes me as being a little bit vulgar.
"Why would I stand on a red carpet and talk about how much I get paid?"