In 1989, when I was 16, I moved into a pub with my parents and my younger brother, Matty. It was highly exciting. I took to barwork as I liked the chat, and also enjoyed the opportunities offered for eavesdropping. I was curious about the adult world and up until then had learned most of what I knew from books. Now I had all these real lives to study. I should write some of this down, I thought, and would scribble into my diary before bed.

We couldn’t believe how busy it was that first Christmas, culminating on New Year’s Eve, when everyone piled out into the main street at midnight and exchanged drunken embraces and warm wishes for 1990. After the pub had emptied and the mammoth job of clearing up was done, we gathered with our staff for a few drinks and the chat turned to resolutions. All the women wanted to lose weight. A couple of people wanted to stop smoking. I announced very firmly that I wanted to write a novel.

I wish I could tell you what Matty said, but I can’t remember. Perhaps he pledged to strive for good GCSE results. If he did, he succeeded, as he got the best grades in school. But by the time the results came, that summer, he had been knocked over by a car and was in a coma after emergency brain surgery. I was by his bedside in intensive care, chattering away to him because everyone from the ambulance drivers onwards had suggested this might help keep him with us and then bring him around. I even tried to pray in the hospital chapel: “Please God, please. Please don’t let him die. He’s too young. He’s too good. I love him too much. Please help him.”

When I wasn’t with Matty, I was at home. I could put on a brave face behind the bar, but when I was alone I gave in to my desolation. I couldn’t believe the enormity of what had happened. I had no words. I knew that unless Matty woke up I could never write anything again. The very sight of my diary made me feel sick. I flicked through the pages, hating my younger, innocent self. I bundled them all up and threw them into the skip at the back of the pub, poking them down beneath the flattened boxes and bin liners full of crisp packets and cigarette ends.

Matty didn’t die, but nor did he regain consciousness. He lived on for eight years in a persistent vegetative state until my parents and I went to the family court and were granted permission to withdraw nutrition and hydration so that he could die and we could, finally, eight years after we suffered the loss of him, have a funeral.

I was bereft. Over the next decade my words drifted back and I tried to make sense of what happened to Matty and how it felt to be the witness at his bedside. But it was always too hard. Surely if I was talented enough to be a writer, then it would be easier and I’d have fewer doubts. Anyway, what was the point? No one would ever want to read such a gloomy story. I tried to write novels instead, but sooner or later Matty would arrive on the page wanting to be heard. I was stuck. Every so often I’d have another go and then give up. I felt like I was destined to fail at this, as I did at everything else, that the car that knocked Matty over had taken me out, too, that I was alive, but only just, and that I couldn’t ask for too much. I’d put my notebooks away in a drawer and try to care about other things.

And then, after the birth of my son, I was filled with a renewed determination. I didn’t want to keep finding myself back at the drawer and realised that the only way I could free myself from this cycle of trying and failing, was to get it all down. I made a new resolution. I just had to do it. It didn’t have to be any good, or even in the right order. And I wouldn’t show it to anyone, so I didn’t have to worry about what other people would think. I read a novel where a priest said that it is our secrets that make us sick. That’s it, I thought. I need to cleanse myself, confess everything on to the page. Only then will I feel better.

It was hard. Often I felt like I was wrestling an octopus as I struggled to tame all the different tentacles of the story. I would feel tired and dispirited, but this time I could carry on, and word by word I excavated myself on to the pages, which eventually became The Last Act of Love. It was a long haul. I was 17 when Matty was knocked over, 25 when he died, and 42 when I managed to finish my book about him. And I did and do feel better. There is an astonishing sense of achievement up for grabs if we can be brave enough to make a commitment and then have the stamina to hold steady through all the ups and downs.

​I am still in awe at the process of writing. The first steps are so simple. We find some paper or turn on a computer. Then we put down some words and fiddle about with them and something magical starts to happen. Writing is the nearest I get to touching the divine and I do feel a little evangelical about encouraging others, so please allow me to suggest it to you as a New Year’s resolution. Much better for us in the long run than any goals around eating less or being less. Don’t resolve to shrink your body! Consider instead the benefits on offer if you are bold enough to mine the self, to disinter your secrets, to finally try to tell that story you’ve been carrying around, perhaps for as long as I did. Or, if that feels a bit much, just write down your life; make a personal record of these interesting times we are living in. What you see on your way to work, perhaps, or what you dreamed, or how you feel just before going to sleep. Three things to be grateful for, four blue things you saw that day, how you nourished yourself or notes from your exercise. Would it not be satisfying this time next year if you had written down a few lines about each day?

​Or grumble. I love to have a good old moan into my notebooks. There is a release to be had in having a private space to let off steam. In this world of hyper communication where anyone with a social media account can feel under pressure to issue press release style comment on every issue and event, there is a glorious privacy to be found in taking up a pen and scribbling down our own thoughts with no aim other than making sense of things for ourselves.​

​The best piece of advice I have for you is that you need to accept that you will have to put in some effort. Unhelpfully, our culture over-focuses on talent. We think writers are special and imagine that those anointed ones simply sit at their magnificent desks in a book-lined room and allow beautiful prose to flow from their pens, all in the right order. From my own practice, and observing other writers, we get along much better when we escape that idealised image and concentrate instead on effort. Most worthwhile activities do involve preparation and graft. We accept that if we want to run a marathon or climb a mountain, we’ll need to work hard. My writing life has become less anguished since I have stopped being cross with myself that I don’t find it easy.

Another cultural misunderstanding I’d like us to jettison is that writing should lead to publication and profit. We can do it purely for pleasure and our personal development, in the way that we might go on a watercolour course, or learn to play the ukulele, or get into running or swimming. Not every pursuit in life needs to have a commercial purpose. Writing offers us stimulation, meaning and purpose and a way to keep our eyes on the stars. Let that be enough in the early stages. Don’t put any pressure on those tender shoots. Though, who knows what might happen? Writing is very much an acorn activity. The important thing is to start and then we may be amazed at what we end up cultivating.

And my resolution this year? Well, I do fancy dabbling in watercolour and ukulele and I also want to finish a book, of course. Recently, when I visited the pub, one of my old friends there said: “You were always going on about writing. And now you’ve done loads.” I hope that more than three decades after I made my first resolution, 2022 will see me finish my sixth book. I know there will be ups and downs, but I’ve learned that it is so worth sticking with it.

Write it all Down: How to Put Your Life on the Page by Cathy Rentzebrink is published by Bluebird on 6 January. Buy it for £13.04 at guardianbookshop.com