Theresa May speaks about the “Great British People” but here we were! With an abundance of good nature and witty homespun placards – and a glorious absence of party political propaganda – only a fortnight ago we marched 400,000 strong for a People’s Vote. And for one day we felt optimistic.

I walked alongside a man in a suit and tie called Mike who had never marched in his life. He worked as an engineer, producing brake systems for an electric car manufacturer.

Mike was from the West Midlands and had come down because the contracts were already drying up in the car industry. Brexit tariffs just will not work for them, it is too integrated with Europe, so production is simply moving across the water.

He was worried for the employees and their families. Whole areas risked being blighted. He couldn’t understand why Brexiteers couldn’t look at the wider economic picture.

It makes you wonder how political ideas take hold in the first place.

Here in Crouch End a new Liveable Neighbourhoods programme has been set up for us, with a £6m pot “for residents to choose schemes which encourage walking, cycling and public transport”.

Along with many people, I had asked for a bus route from Crouch End to Highgate and then on to Hampstead High Street, taking in the Royal Free Hospital.

But my heart sank when I went along to its “community workshop” on Monday. The conversation had already been manoeuvred and was now “a new type of thinking”.

Maps had been drawn up to show a new radical Crouch End – with parking abolished alongside the shops and no entry lines at all the feeder road junctions to the Broadway.

There was talk of number plate recognition checking that only residents were using certain roads.

The idea looked nice on a map. But no one had stopped to think about how the Crouch End economy needs visitors and transportation. Crouch End is a success story: when many of the high streets are dying, it manages to thrive. It sustains well over 200 shops, most of them quality independents, and countless small businesses. Stopping the parking will take customers away, and could be critical for profit margins.

I spoke up for carers who often have to transport frail or ill family members – they do not always have a blue badge.

There will be times when people need to take their car, and a limit to how many heavy shopping bags they can carry up the hill – especially if they’re ill or frail or heavily pregnant, or life’s just really busy.

Let’s at least trial a bus service to Highgate and Hampstead – it could help everyone.

If we have learned one thing from Brexit it is that an idea has to be thought through – the economy must never be jeopardised.

To paraphrase former Haringey councillor and the now recently resigned minister Alistair Burt: you can pull a thread and before you know where you are, things have got very, very difficult.