The farmers’ protest was best summed up in two images: real tractors driven by farmers around Parliament Square, and next to them a collection of toy tractors hawked by their children.

They illustrated the essence of the farmers’ argument: that there is a deeply ingrained cultural expectation that they will pass their farm on to the next generation.

For many, this feels like a deep responsibility that extends high up their family tree, and so the expectation falls on them to ensure that what their ancestors did for them, they also manage to pass on to their sons and girls.

As a journalist, I love covering protests and marches in Westminster.

They are a vital voice in the never-ending conversation of our democracy.

I have been showing up to them with a microphone and camera for 20 years – to observe and scrutinize those who make the most of their cherished right to come to London and – often – insult the government.

I love them because people who are passionate enough about their cause to travel to the capital and then make a public, almost certainly controversial, argument are often worth listening to and should also be vigorously challenged.

And, to me, these conversations offer insight not only into what protesters think, but why they think it.

This gathering of farmers left me with three thoughts:

First, as we have already explored, there is enormous power in the cultural expectation to pass on a farm to the next generation.

It is not just a business, but an identity, a belonging, a geographical anchor – and the prospect of not being able to transmit it arouses enormous anger and emotion.

This is a big part of why this argument has become so loud, so quickly.

Second, contested notions of fairness are so often at the heart of the most controversial political arguments, and this one is no different.

The government says existing inheritance taxes are neither fair nor sustainable – given that everyone else wealthy enough to pay them has to pay 40% and farmers pay nothing.

Ministers also say the exemptions have encouraged the wealthy to buy farmland – thereby increasing its value – mainly to avoid inheritance tax.

And, as they are at pains to point out time and time again, they insist that the vast majority of family farms will not be affected and that those that are will be charged 20%, or half the rate charged to any another person within reach.

Plus, they say, schools and hospitals desperately need more money.

Others say farmers are a vocal and well-organized lobby group that seeks to protect their often considerable wealth and perpetuate one privilege to the exclusion of others.

And all of this brings us to the third big question: what does it mean to be rich?

Talking to farmers, very quickly our conversation would often be about very big numbers – we were talking about assets amounting to a few million pounds.

These are huge numbers that speak to considerable wealth and yet farmers insist, for two reasons, that they are not rich.

Their annual income is often modest, they point out, and they evaluate their farm not in numerical terms, but in emotional terms. The prospect of selling it horrifies them; transmitting it is what they seek to do.

Farmers insist they are determined to continue their campaign.

Ministers insist on their determination to pursue their plans for change.

You can choose to sympathize or not with the farmers’ arguments – or those of the government, or not – but the protests offer insight into what contributes to the views of many farmers, and why they seem unlikely to back down . time soon.