His health issues are a known fact, but it never comes in the way of Amitabh Bachchan's commitment. The megastar believes if you promise something, you cannot backpedal.

"That's commitment. Once you have committed yourself to a function or a programme, then you have to go and do it irrespective of...nobody is going to understand your health condition except you...somebody would say this person is making an excuse, so it's always wise to comply with it even at personal cost, " Amitabh, who celebrates his 70th birthday Thursday, told in an interview.

Asked where does he get all the energy from, he dismissed the question saying, "You all are unnecessarily saying it as if it's a huge achievement or big thing. It is nothing like that."

He suggests that one must be sure about one's action.

"Before doing anything, you must think whether I should do it or not. Once you decide I want to do it, then later whatever happens you should fulfil it."

Even after so many years, fan frenzy surprises Big B.

"This is their respect...what more can I say...ever since I met with the accident in 'Coolie', they have been coming to see me. At times I am amazed and surprised to know what they want to see in me, " said the actor.

"I am grateful to them that they come. My duty is to meet them, sign some autographs, and click some pictures with them, " he added.

From the reigning superstar of the Hindi film industry, he has earned the status of megastar. But he says that he doesn't believe in the epithets.

"You (media) create this wonderful epithets superstar, legend, icon...I have not made them, neither have I believed in it. I look at myself as any other ordinary person. I am an ordinary person, a human being with two eyes, two ears..., " he said.