I was talking to a friend last week – a sensible, fit, accomplished and interesting woman of my age – when she suddenly said: "I can see now how easy it would be to develop agoraphobia."

She explained she felt that her life has shrunk during the past two years and how when she has a reason to go out, she has a strong compulsion to return home immediately afterwards.

She told me that before Covid, especially if she walked into the city, she would never have gone for one purpose only. Instead, she would have visited the library, met someone for lunch, taken a dance class and picked up some shopping.

Like me, she’s a widow and well aware that it’s very easy to become insular when we spend too much time alone, but she said that sometimes it feels like a real battle to leave the house at all.

She’s not alone. Vast numbers of adults – including those much younger than us and people with partners and families – feel the same way.

It is, without doubt, a legacy of the pandemic.

I must say that when I began writing about coronavirus in March 2020, I was completely clueless about how much change it would bring to our lives and attitudes; changes that may continue to evolve for ages. It’s been a huge shake up. There’s still loads of uncertainty, and it’s hard. No wonder our nerves are on edge.

There are other factors of course. Plenty of adults have looked at how much they used to spend on eating and drinking out, on holidays, clothes and entertainment, and have decided that it was excessive. As a consequence, they’ve vowed to curtail their extravagance and stay home more. But is there also an undercurrent of fear in their decision? Probably.

A male friend, who is by nature very sociable, told me recently that nowadays, he finds himself wanting to be in his own house much more than he used to. Initially, he believed that lockdowns had made him lazy. But now he’s realised his emotions are more complex and to do with a perception of home as a safe refuge.

It’s hardly surprising though. In the western world, we were dumbfounded by how virulent and deadly Covid-19 was. We used to assume such catastrophes only happened in far-off countries. The intense shock we’ve suffered lingers on in the crevices of our minds and one of the results of that, is our more pronounced nesting instinct and an urge, when we’re out, to scurry home swiftly, like a frightened rabbit bolting for his burrow.

However, despite this being understandable, I believe we now have to fight these impulses to hunker down at home. The majority of us are in much less danger from the infection – because of vaccines and the availability of tests – than we were a year ago. And I feel it’s time to be bolder for the good of our mental health.

Last week, I went to London for a meeting. Afterwards, I felt a powerful desire to skedaddle straight back to Suffolk, but I made myself resist this impulse and rather than head for the station, I walked to another part of the capital and popped into a place I used to work and had a cup of tea with former colleagues.

Next, I went to an exhibition at a gallery. Then I strolled through the fashion departments of a couple of department stores, which felt really strange, as I buy clothes online these days. And finally, I had supper before catching a train back.

By the time I arrived home, it felt like the middle of the night – which is pathetic as it was only 9.30pm But the next morning I realised that I felt very cheerful. More than that, I was pleased with myself that I’d spent a day in a way that would have been entirely normal before ‘the plague’.

Now I plan to continue to push myself to get out and about more and, though we need to remain careful and vigilant about infection, I believe it might help you to do the same. The harsh truth, and this is very important, is that a descent into poor mental health can be rapid, but recovery rarely is.

And there’s a further reason for engaging more with life beyond the home and that is that it will help preserve the businesses and organisations we used to enjoy in pre-Covid days – many of whom are struggling.

So, if shopping, going to the theatre, cinema, concerts, or sporting events, doing exercise classes, eating in cafes, coffee shops and favourite pubs and restaurants are activities that enrich our lives, we need to take on board that if we don’t do them, they may cease to be available, and life in the future might therefore be a somewhat dilute version of what we would like.

The old phrase ‘Use it or lose it’ comes to mind. It may never have been more apt