The veteran MP had certainly made the most of the day before lunchtime, having spoken in the House of Commons three times in the few hours of its sitting before we meet.
He had asked Transport Secretary Grant Shapps about train lines in Yorkshire, and then called on the Speaker of the House, Jacob Rees-Mogg, to bring forward a debate on Russian money “swilling around in London”. Then, he told Rishi Sunak he is the “most incompetent Chancellor” he had ever seen.
Labour’s longest continually serving MP entered the Commons in 1979, as Margaret Thatcher moved into Downing Street.
More than four decades later, Mr Sheerman has announced that his name will not be on the ballot paper next time the country goes to the
“I’m not getting any younger,” he tells The Yorkshire Post, explaining that he was considering stepping down at the last election in 2019, but the Labour Party “was in trouble” at the time.
He has never made secret the fact that he was not a fan of former leader Jeremy Corbyn, adding: “I think people were aware we were going to lose seats, and people said to me: ‘Barry, if you don’t stand in Huddersfield it could be one of the casualties’.
“Because I’m quite well-known, they thought I could hold it, while others might not.”
His Conservative competition at that election was former Huddersfield Town chairman Ken Davy, who he describes as a “formidable opponent” who gave him a “glorious contest”.
Election campaigns involve long days, many miles walked and hundreds of doors knocked. Anybody would be forgiven for not finding them an enjoyable experience, but despite having done so many, Mr Sheerman says he still enjoys the “exhilarating” battle.
“You’ve got to like it,” he says.
“I’ve always said that anyone who is at all sensible when they’re getting up in the morning for canvassing, if they’re looking forward to it, they’re mad. I never look forward to it.
“But when you get there and you knock on that first door and either you get something really lovely or really quite abrasive, the adrenaline starts going and it’s fun.”
He adds: “If it’s not fun to do, why do it?”
Mr Sheerman spends nearly an hour in his Westminster office talking about his achievements and the items still left on the to-do list.
The top-floor rooms look out over Parliament Square and New Palace Yard.
However, despite the world class view, visitors cannot help but notice the very personal decorations.
As well as countless awards and campaign posters from decades gone by, hand-drawn crayon pictures and framed photographs of children and grandchildren line the shelves behind the desk and windowsills.
Throughout our chat, Mr Sheerman interjects with occasional stories about his children and grandchildren – one of whom has won a place at Yale.
But it was a family tragedy that motivated the switch from a career in academia to one in politics.
“We had this happy, contented, successful, wonderful life, but our first little girl died at birth,” he says.
“It’s really shocking. It’s hard to reconcile with, the poor little thing.”
Mr Sheerman describes himself as being the “strong man” in the months following the loss, supporting his wife.
However, as the next year rolled around, he recalls “getting sore throats, losing my voice, having no energy”.
A trip to the doctors encouraged by his wife was where he first heard the suggestion that he was suffering from “the posh word for depression”.
“And out of that came ‘I don’t want to talk about economics and politics’.
“I didn’t want to teach any more,” he says.
“I wanted to do it. I wanted to change the world. That was a turning point for me. I had to get out and do it rather than teaching.”
In the years since, the 81-year-old believes he has become a “professional parliamentarian” who loves the “connection with his constituency”.
But he also proudly calls himself a “social entrepreneur”, which is what he says he will carry on doing after his departure from the SW1 postcode.
“I’ve started over 50 different enterprises and charities,” he explains. “Many of them are where I will continue to be active.
“I’m still heavily involved in an international organisation, I’m very involved in the sustainable towns movement.
“I was very much involved in the Clean Air Commission, and I will also continue my work with the Autism Commission.
“So there’s lots of stuff that I’ve lined up that I will carry on doing.”
However, Mr Sheerman maintains that he is not on the wind-down yet before he steps away from the House of Commons, with his eye still on “the next big task” of “bringing back buzzing town centres” still high on the priority list.
“I still hope to be able to do quite a lot about that in those next two years,” Mr Sheerman says. “As my wife says, ‘You’ve still got two-and-a-half years to make mischief, Barry’.”