New Delhi, May 31 (IANS): It's difficult to adapt books into movies, says actor R. Madhavan, who is still basking in the success of "3 Idiots" based on Chetan Bhagat's book "Five Point Someone".

"A director can get an idea from a novel, but making a film from a book is difficult. Writing the screenplay is a challenge. In '3 Idiots', we had to change a whole lot of things," said the actor, who was in the capital Sunday to promote long-time friend N. Sampat Kumar's book "Love on Velocity Express".

The Mumbai-based author's work has been published by Cedar Books and was released at the Chelmsford Club here.

Madhavan said he had spent several nights on Mumbai's Juhu beach with Sampat Kumar discussing philosophy while he was struggling to get a hold in the film industry.

The 40-year-old actor, who played a college boy to the hilt in "3 Idiots", continued showering praise on director Rajkumar Hirani for having deftly adapted the written word onto the big screen.

"Rajkumar Hirani did a wonderful job as a narrator and director. He consulted everyone and did what he thought best for the movie. If an actor is asked to make a wish list, the desire to make movies with Hirani should top the list. He is such a meticulous director and his movies are so refreshing."

Clad in a black T-shirt and blue denims, Madhavan said he was loving the popularity he enjoys both in the south and the north.

"I love the idea of being identified as Maddy Paaji after the success of 'Three Idiots' and 'Teen Patti'. In south I am referred to as 'Maddy Thambi'," he said.

The Tamil heartthrob, who was born in Jamshedpur in Jharkhand, said he would "head to Monte Carlo next month to shoot for his forthcoming Tamil movie".

"I am working with Kamal Haasan and Trisha for my next Tamil production. We have not yet decided on a name for the movie," he said.

In Bollywood, the actor said he had just completed work on "Tanu Weds Manu", a romantic comedy directed by Anand Rai.

"I have not been home for the last 48 days and in the past 24 hours, I have changed six flights. I am desperate to go home," the actor said.

Though he had come for a book launch, Madhavan candidly said he was "not much into books".

"In school they made me read so much that I don't read story books any more. I gather my information from audiovisual means," he said.

The actor said he would stick to acting for the time being but added that he was "capable of directing or producing" as well.