Shahid Kapoor's introvert nature and Kareena Kapoor Khan's high-spirited avatar made the audience fall in love with their characters of Aditya Kashyap and Geet Dhillon.
Imtiaz adds he would rather not reveal the changes he wanted to make as the film continues to be a fan-favourite.
The director tells PTI, "There are lot of things that I would like to change. Now that 10 years have passed and people are still loving it, I would resist myself from doing that, otherwise I will get beaten up by fans for doing that."
Talking about why he thinks the film was able to connect with the masses, Imtiaz says it was not the usual love story where the boy meets girl and they fall in love.
More From This Section
"I feel elated that people love the simplicity of the movie. It is a bit different. It is about positivity, it gives you hope, makes you smile, especially that part when Geet, on the terrace of her building, tells Aditya - 'Life is a game. Let's enjoy it.
"Getting stressed about it doesn't make it easier'. I think that was the icing on the cake in the film."
In the second half of the film, both Geet and Aditya undergo drastic role reversals.
Talking about the chemistry between Kareena and Shahid, Imtiaz says it is not about the stars sharing an equation.
"... Else it will be the same for every film. The chemistry is between characters of a story... The actors are playing those characters, that's why they look interesting together or not," he adds.
Apparently, Bobby Deol and Ayesha Takia were initially considered for the lead roles.