In a moment I will introduce you to my new hero in the Brexit war. But for now, I am lying down with my eyes closed.

Floaty music is playing in the background and other people are sharing the floor. We are told to tense the muscles in our scalps and then let them relax. Same goes for our creased brows, our chins and all other muscles in most destinations heading south.

Once instructed in how to relax, we are told to lie there for five minutes, eyes still closed. The air-conditioning unit starts up, quite nosily. “And are you listening to the air-conditioning or can you cut that noise out?” we are asked.

Nope, that noise is still there. But this is OK, this is what relaxing must feel like.

“Do you need to relax?” my pilates teacher had asked when I signed up for this session. “Oh, always,” I joked.

Doing nothing much is harder than it looks, different to my usual Sunday morning sweat. I forget we are meant to be doing nothing and thoughts flurry through my mind. You know what, one militant flurry says, you could write a blog about this. Pipe down, says the less militant flurry, we’re not meant to be doing anything.

At the end, we stumble back into daylight.

A good session, but I think relaxing might take more practise. Pilates, by the way, is a new pursuit for Sensible Old Julian. Militant ‘Young’ Julian can scoff all he likes over his red wine while nursing his squash sprains, but pilates is good. Stubborn Old Julian still swears at squash balls and curses those shuttlecocks, but at least Sensible Old Julian gets a turn at all the stretching and core-strengthening one morning a week.

After all that relaxing, I concentrate on staying upright while cycling, far from a relaxing activity in this city.

Here, then, is my hero for our age. Hazel Jones, 71, is a retired teacher and a widow. This weekend she was unmasked as the person responsible for writing hundreds of anti-Brexit messages on walls across Wakefield, West Yorkshire.

Hazel was filmed chalking the message “Brexit is based on lies. Reject it” on a wall outside a local grammar school. In an interview with The Times, she admitted she had been leaving similar messages across the town since the referendum in 2016.

“We all have to do our bit,” Hazel said. “I think it’s very important that people are made aware of the imminent catastrophe that we will be faced with if Brexit goes through. My generation has fouled up the prospects of younger people, so it’s my grandchildren that I’m doing it for.”

So much to admire here. First, the messages are small and neat, and written in chalk because it washes away. Then there is the splendid Britishness of “we all have to do our bit” – a lovely riposte to all the Brexit party brigade tearing pages out of the Second World War scrapbook again. And then there is the low-tech nature of Hazel’s rebellion, requiring a stick of chalk, a brick wall and a smidgen of courage.

While half the world is sending out angry tweets, or writing too many Brexit blogs, here comes Hazel Jones with her stick of chalk. Her old-school protest has more impact than all those digital assaults on Brexit.

Hazel tells The Times that she’d better stop now – and she also says of being caught on video, “Had I known I was being filmed I would have dressed up a bit more.”

Thank you, Hazel, with that remark and your rebellious stick of chalk, you have cheered me up.