The United Nations declared Monday 20 March to be International Happiness Day; what better time to revisit a brilliant column by Carla Carlisle on what happiness really means.

This article was originally published in life in November 2011.

A padded envelope arrived that’s been recycled so many times it looked like an objet trouvé. It’s from my friend Katie, who once sent me a carton of coffee-almond-fudge frozen yogurt for my birthday. Packed in dry ice in Burlington, Vermont, where the first Ben and Jerry’s ice-cream parlour opened, it didn’t survive the flight and, a year later, Ben and Jerry’s was bought by Unilever, but heck, it’s the thought that counts.

Which is what worried me as I opened the package and pulled out a new paperback book called The Happiness Project: Or, Why I Spent a Year Trying to Sing in the Morning, Clean My Closets, Fight Right, Read Aristotle, and Generally Have More Fun. What was she thinking?

For a start, Katie never buys anything new. I look for smudges of blackberry jam. I sniff for her scent: a mix of udder cream-her hand cream of choice or Vaseline, her cure for everything. All I detect is the smell of newness.I then read the back cover. It seems the author (the photograph shows a toothy, clean-faced Gretchen Rubin) had an epiphany one rainy afternoon on a city bus. ‘The days are long, but the years are short,’ she realised. ‘Time is passing, and I’m not focusing on the things that really matter.’ In that moment, she decided to dedicate a year to her happiness project.

As I gazed at the book, all I could think was that Katie got this free. Why else would she send me a book that, in big letters says ‘Start your own happiness project-guide inside’?

I batted out an email. Me: ‘Package arrived. Do you think I’m unhappy?!?!?’

Katie: ‘14 emails moaning you don’t have time to clean out your cupboards/tap dance/bake bread/halter-train calves/get decent haircut/go to movies/answer letters. Last month’s emails complained of chestnut trees dying/canoe paddles stolen/favourite cake lady leaving the farmer’s market/wine harvest wiped out/unread books piled up/TV going digital.’

Me: ‘What did I say nice about my life?’

No reply.

Although I think of myself as cheerful and easy-going (sweet), I admit I do buck and snort a lot these days. Each day, I vow to feel grateful for my country life/the man I married/the dog at my feet/enchanting turkeys/adorable sheep/a son who calls home whenever I leave a message saying that I’m cancelling his phone because it’s obviously been stolen. But I wake up with Radio 4’s Today, so all peace of mind plunges like a stone in water.

Despite studies that show genetics account for about 50% of one’s happiness level, I’ve acquired a late-in-life melancholy that’s hard to shake. Melancholy and fury. I despair for Coptic Christians/unemployed graduates/Judith Tebbutt kidnapped in Kenya/a friend whose tooth troubles have robbed him of his natural ebulliance. I rage at the idiocy of Liam Fox. And yes, the paddles were stolen and the horse chestnuts look miserable and we all know Greece is going to default and if the floods in Pakistan and Thailand/drought in Somalia and Kenya aren’t climate change, what the hell is?

I’m starting this project slowly. Not just because I nag and I want to clean out my cupboards and I bought the Everyman Essays of Montaigne a year ago and haven’t read a single one. I want to raise my happiness level because it’s when your life is pretty good that you need to develop the habits that put you in good stead for the adversity that will come.

The beginning seems simple. Walk more. Nietzsche said ‘All truly great thoughts are conceived while walking’, so I hope you will soon notice an improvement in this space.

And sleep more. Few of us get enough sleep and sleep deprivation impairs memory, weakens the immune system, slows metabolism and fosters weight gain. A study shows that getting one extra hour of sleep does more for a person’s happiness than getting a $60,000 raise.

I bet you’d like to know more about that, but I’m afraid it’s time to turn out the light.

Carla Carlisle