One thing is terrifyingly clear: if optimism is contagious, so is pessimism. The Labour party doesn’t seem just miserable because it lost; it imparts despair and anxiety.

These are not unfamiliar feelings to many. The last week of January is said to be depressing but it was also when Brexit happened and change was in the air. Mood matters. Those who fail to read the mood of the populace are destined never to govern it, but we have very few ways of talking about feelings in political terms.

If you largely speak of your constituents as victims then you disempower them

Do you remember the brief time when we did? Instead of talking about infrastructure and immigration, we talked about something much more intangible. Happiness: Lessons from a New Science, the economist Richard Layard’s book, published in 2005, had a massive impact on public discourse. It started asking government to be concerned with something even more vague than happiness: “wellbeing”.

Wellbeing, like happiness, is self–reported. You can ask me how I am. You don’t really want to know, but we can all tick the boxes. The statistics on mental health – about one in four Britons will experience a mental health problem each year – are really telling us that many of us are very far from any sense of wellbeing.

Joining the dots between policy and individual happiness became mainstream. David Cameron tried to talk about “a national happiness index” as the post-crash economy was in turmoil. He had addressed this at a Google Zeitgeist Europe conference, saying there was more to life than money. GDP was not the answer, apparently, but GWB: general wellbeing. This, he said, was a key challenge for politicians.

Those were the days, my friend … and then he unleashed George Osborne and let him hack away at the welfare state and basic benefits, to ensure that wellbeing and even getting by were but distant dreams.

We know social inequality causes depression and stress. We also know that this country has been a very anxious place for the past few years and while many are upset by the Tory landslide and Brexit, others feel a sense of resolution. Businesses are saying they can at least plan ahead, but many ordinary folks are feeling a fall in life satisfaction.

The infrastructure that provides the conditions for happiness have been decimated: community centres and youth clubs and schools (as something other than exam factories). Meanwhile, town centres have been suffering. Every time we hear of another big store closing down we know there will be another boarded-up high street. Growth isn’t infinite, and shopping as a leisure activity is mostly a reminder of what you don’t have rather than an activity that brings any sort of meaning and connection.

The organisations that do provide social value are small, local and arise organically, such as volunteer-run cafes and community gardens. They are the very opposite of the centralised state enterprises that the Corbyn cohort dream of. It may not have intended to, but Labour’s pessimism has allowed Boris Johnson to surf this wave of optimism – as fraudulent as it may be – because it signals a break not so much with the EU but with miserablism.

This really matters in ways that politicians appear still not to get. If you talk only of bad things, it is hard to appear as someone who loves their country. If you largely speak of your constituents as victims then you disempower them. Corbyn and his acolytes really have owned their Eeyoreness. They’ve made it easy for someone with a skewed but, yes, happier vision of the future to walk all over them.

Positive psychology, a theory that says external circumstances make almost no difference to our own happiness, is flawed. No, I really don’t want to hear anyone talk about their gratitude journal. Count your blessings in private.

Many things are beyond our control, but actually the things most people give thanks for – friends and family and relationships and jobs and housing and money – do matter. Talking nonstop about austerity and the climate emergency and coming recession has not made people more energised or leftwing.

Instead they have become passive and anxious. Jeremy Corbyn may as well stop doing prime minister’s questions and just tunelessly sing Heaven Knows I’m Miserable Now. Wellbeing, contentment – no one associates them with Labour. They seem like ideas from another age. Just listen to the words of Winnie the Pooh: “Don’t underestimate the value of Doing Nothing, of just going along, listening to all the things you can’t hear, and not bothering.” The bear gets it.

• Suzanne Moore is a Guardian columnist