Saif Ali Khan is on cloud nine. He is riding the crest of the successful Hum Tum. But he is not being carried away.

"Life has its ups and downs," he says. "Right now, I am on the up side of life. It feels nice to taste success. But there will be downs. Both [failure and success] should not be taken too seriously."

Khan, who has played the unconventional hero in films like Dil Chahta Hai, Kal Ho Naa Ho, and Ek Hasina Thi, says, "Yes, there has been a change in the characterisation in films. Imperfect characters are more interesting than perfect ones."

So, has success come late to the Chhote Nawab? "It [success] came when I deserved it. Though I would have loved it much earlier," he says.

Khan does not regret choosing acting over his father's profession, cricket. "I am doing far well for myself as an actor. Though of course I do feel bad for my father [Mansoor Ali Khan Pataudi] to see that all of us have followed my mother's [actress Sharmila Tagore's] profession. At the family dinner table, he is the only cricketer surrounded by actors. Maybe my son [Ibrahim] will take up after him. He displays good hand-eye co-ordination. He knows how to handle the bat."

Khan is the newly appointed brand ambassador for Royal Stag. Why endorse a liquor brand? The actor claims he has 'studied' the product. "I have a moral conscience and will never cross the line," he says.

"Featuring as the brand ambassador for a quality product comes well within that line. I will not endorse everything and anything for money. Medical studies have proved that a little alcohol is beneficial to health. If it [alcohol intake] is within limits there is nothing wrong in endorsing such a product," he says, admitting that he is an occasional drinker.