Despite completing 40 years in Bollywood, the ageing actor is not the one to rest on his laurels. He is busy shooting for Ram Gopal Varma's 'Department', despite getting injured on the sets of the film. He is also hosting the season 5 of 'Kaun Banega Crorepati (KBC)' on Sony TV.
"One of the best ways to bring in birthdays is to be working at what you need to be working on...I work because of I need to ....love!!," Bachchan said.
The actor returned home at midnight after shooting for the diwali episodes of KBC and said he could just make it home in time for the clock to strike 12 and for the family to wish him. "The greatest joys of life are in the simple wishes," he said.
Immediately afterwards, he settled to interact with fans from all over the world on his blog and micro-blogging site twitter.
"It is past midnight! It is my birthday today! It is another year gone by! It is stepping in to the 70th year for me! Thank you! Have just been released from the clutches of work form KBC... and here to thank you all for the love and affection you shower!!
"They ask me what I wish for my birthday .. why only on the birthday, it should be everyday... I wish another day to pass in peace ! Thank you all once again for all the Birthday wishes ... I am so humbled and filled with pride .. you make it all happen .. my love," he said.
On his blog, Bachchan recalled that he was born in a small private maternity outfit run by a missionary Dr Brar, in the most-crowded market area of Allahabad.
"I was brought home by my parents in the best possible transport machinery that they could afford – a tonga! 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. 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 wrote.
"As I step into the 70's unabashedly, I need to thank several of those that I feel were the ones that seemed distressed with the number of my age. But no they are not so! When they speak of age and involvement, why must we only look upon the aged, onto those that show the ravishes of time and the hunger of recognition. I would imagine that we must let the world be as it is and allow whatever shape it desires to take vis-a-vis individuals," he wrote.
Bachchan gained popularity in the early 1970s as the 'angry young man' of Hindi cinema, with films like 'Agneepath', 'Trishul', 'Deewar', 'Zanjeer'.
Year 2011 saw Bachchan rekindle his 'angry young man' image, that he is best known for, in 'Bbuddha Hoga Terra Baap'. But on the personal front, he is set to become a grandfather again, as son Abhishek and daughter-in-law Aishwarya Rai are expecting their first child.
His other film, 'Aarakshan' that hit the screens this year got mired into controversy due to its subject – 'reservation'.
Bachchan even turned 'item boy' for a song titled 'Go Meera'. He was seen in a colourful and flamboyant avatar, dancing to his own golden hits like --'Khaiyeke Paan Banaras Wala', 'Pag ghunghroo baandh Meera naachi thi', 'Rang Barse', 'Sara Zamana' among others.
"All these years, I have been desperately waiting to be called an item boy. Please call me that. I feel with this song, my wish has come true...and I am satisfied," Bachchan had said.
A few months back, Bachchan broke the news of his daughter-in-law Aishwarya Rai expecting a baby.
"And so to becoming a Dada! The excitement and the joy of the first Bachchan coming after my brother and me. Nana I was, but now Dada!!," he had said on a social networking site.
The actor had said that he felt the grandchild would bring the child in him.