Greetings from well-wishers make him feel "74 years young", Congress leader P Chidambaram, in jail on charges of corruption, said through his family on his birthday on Monday, while his son told him "no 56!!! can stop you", in an apparent swipe at Prime Minister Narendra Modi.
The former Union minister said that his thoughts on the day are on the economy and added "may God bless this country".
Birthday wishes for Chidambaram, who is in judicial custody in Tihar jail in connection with alleged corruption in clearances given to INX Media when he was finance minister, came from his party colleagues as well as his son Karti Chidambaram, who wrote a two-page letter to him.
The veteran Congress leader thanked everybody and said his spirits had lifted higher.
"I have asked my family to tweet on my behalf the following:
"My family have brought me greetings from friends, party colleagues and well-wishers. I am reminded that I am 74 years old. Indeed I am, but at heart I feel 74 years young. Thank you all, my spirits have been lifted higher," he said on Twitter.
In another tweet, he said his thoughts today are about the country's economy.
"Just one statistic tells the story. Export growth in August was -6.05 per cent. No country has achieved GDP growth of 8 per cent without exports growing at 20 per cent a year," he said.
"May God bless this country," he added.
In his letter, Karti said, "You are turning 74 today, and no 56! can stop you. Although you have never been one for grand celebrations, and nowadays in the country, we seem to be making grand celebrations out of every little thing, your birthday is not the same without you with us."
Karti, who is himself an accused along with his father in the INX case, made the apparent reference to Modi, raking up a 2014 statement by the prime minister where he had said only someone like him with a "56-inch chest" can take bold decisions.
"We miss you, your absence tugs at our hearts, and we wish you were back home to cut a cake with all of us. But of course, in today's day and age, turning 74 is nothing compared to turning a 100 days old. But, I have faith that you too will come out guns blazing against this elaborately staged political drama and for now, we all await that hard-fought glory of truth," he said.
Karti also said that at least they were able to visit him, and pass on his messages to the public via tweets, but according to a recent Supreme Court order, MPs visiting their colleagues in Kashmir were asked to refrain from speaking to the press.
"So all in all, the BJP government celebrated their unpropitious second innings and they couldn't have possibly found a better time to silence you," he said.
Chidambaram's party colleague Jairam Ramesh said the Union minister is going through an "agnipariksha" and will come out of it vindicated.
"Today PC turns 74. It is an agnipariksha he is going through but he will come out of it vindicated. I have worked very closely with him since 1986 and it has been a great privilege and education doing so. My thoughts are with him," he tweeted.
Party leader K C Venugopal also sent his greetings on Twitter.
"Being challenged in life is inevitable, being defeated is optional. I am sure that the vendetta politics can't defeat you. Happy Birthday to P Chidambaram."
Congress leaders Manish Tewari and Shashi Tharoor also wished Chidambaram and said they stood with him.
The Mahila Congress quoted tennis ace Rafael Nadal while wishing him.
"Following his US Open victory, Rafael Nadal said, 'The emotions sometimes are impossible to control and I tried to resist but it was difficult,'... Happy Birthday to @PChidambaram_IN ji".
Chidambaram has been lodged in Tihar jail since September 5 by a Delhi court in connection with the INX Media corruption case.