Being the only lead actor in "Student Of The Year" (SOTY) with no film background, Siddharth Malhotra felt he was at a slight disadvantage. Nevertheless, he enjoyed the ride, which came to him as a surprise from director Karan Johar.

Siddharth, a model-turned-actor, worked with Johar as an assistant director earlier. In "SOTY", releasing Oct 19, he shares screen space with Mahesh Bhatt's daughter Ali and David Dhawan's son Varun.

He says he found it tough to be as dramatic as the other two, due to his non-filmy background.

"The only disadvantage in being from outside is doing filmy things. I'm not so dramatic and not comfortable doing over the top things. When you look at Shah Rukh Khan, it's not what he sings on screen, but how he sings too. He sings (lip syncs) with so much passion and love. This was a challenge at least for me," Siddharth told.

"These guys (Alia and Varun) have seen this right from the beginning," he added.

Siddharth, who hails from New Delhi, says he couldn't believe it when Johar gave him the chance of being a part of the movie. And there was no way he could refuse it.

"Karan Johar doesn't offer you a film, he announces it. Who are we to refuse him? When he told me he would be directing it, I asked him why he wanted to take me," he said.

But acting has been a tough job, he admits.

"Being an actor is not easy. You have 13 to 14 hours-long work schedules and hardly get anytime to sleep. You need to keep working out so that you look good and perform well," he said.

Siddharth came to Mumbai five years ago in the hope of signing a film. But the project didn't materialise. After being prodded by a friend, he decided to take up the job of an assistant director to enter Bollywood.

He established connect with Johar's Dharma Productions.

Working as an assistant director on "My Name Is Khan" made it easier for Siddharth to understand the inner workings of a film set, and that experience helped him for his acting debut as well.

"You know what not to do. You understand the importance of something which an assistant director comes and tells you. You understand production deadlines. You understand the workings of it because you have been that person," he said.

It was on the sets of "My Name is Khan" that Siddharth met and got to know his co-actor Varun as he too was an assistant director on the film.

"We had a lot of time to know each other off screen. We travelled together, went to Los Angeles together and stayed together," he said.

After a romantic comedy film like "SOTY", Siddharth says he would love to do an action film. The actor might be taking up another film with Dharma Productions soon but didn't want to talk about it.

"There is a film that is being talked about, but nothing has been finalised as yet. It's too early to talk about," he said.