"I was born today ! 11th of October 1942 in Allahabad in a small private maternity outfit run by a missionary Dr Brar, in the most crowded market area of the city, Katra. I was brought home by my parents in the best possible transport machinery that they could afford - a tonga!" Amitabh wrote on his blog.
"Wrapped in a 'gudari' I still refer to many that I am a 'gudari ka lal' - a human that is affiliated with the cheapest form of clothing. I loved being in that form and still love it, " he added.
Amitabh says he finds himself close to the people who have lead a life in adverse conditions.
"I have noticed on many occasions that the life and the style of those that live in such conditions, is closest to me in temperament. There is a certain sense of attachment every time I come in close contact with people and circumstances that narrate to me stories of the time, " he said.
"That is my most alluring possession. The complete ease that I feel and identify with when in the company of those that inhabit those lands, " he added.
And what does the actor wish on his birthday?
"I wish another day to pass in peace! One of the best ways to bring in birthdays is to be working at what you need to be working on... I work because I need to... love !!" he wrote on his Twitter page.