If you’re feeling full of joie de vivre this week, it could be because of the weather, an unexpected phone call from an old friend you haven’t heard for a while, or the relief you felt when your car passed the NCT. Or maybe it’s because this is the week we celebrate International Day of Happiness.

It’s easy to become cynical about the designated days that seem to have been created for every occasion – from Lima Bean Respect Day to National Ballpoint Pen Day, and even Working Naked Day (although that at least is still confined to America, you may be pleased to know).

Let’s be honest, none of us like being told what to do or how to feel. But you can’t have too much happiness in your life, can you?

Every year on 20 March, people around the world come together to celebrate International Day of Happiness. More than just another date on the calendar, it represents a global movement to building a happier, more-inclusive and resilient world.

The theme for this year is happier together, a gentle nudge about the importance of being connected, and part of a larger community.

The spring equinox falls on the same day, giving us another reason to be happy. While it may not be warm enough yet to spot the early butterflies flitting by, the birds are warming up their vocal chords for the dawn chorus and, as the long, dark nights yield to longer, brighter days, there is a palpable sense of hope in the air.

Happiness means different things to different people. For some, it’s champagne and afternoon tea in a luxurious five-star hotel. For others, it’s a cup of coffee, a slice of toast by their fire, and a soft, warm bed to sink into.

My dogs are always happy. They live in the present, not dwelling on the past or worrying about the future. All they want is a warm lap to rest their head on, a piece of chicken that ‘accidentally’ falls from the dinner table, and a roll in something smelly, and all is right in their world.

Likewise, small children, seem to need no more than a game of peek-a-boo, a bunch of keys to chew on, and a pair of hands to push them higher and higher, as they squeal with joy from behind the bars of the baby swing.

My dogs are always happy. They live in the present, not dwelling on the past or worrying about the future. All they want is a warm lap to rest their head on

Like many parents, what matters most to me is knowing that my children are well. The old adage that every parent is only as happy as their unhappiest child resonates strongly. There is nothing that brings me more joy than hearing the ringtone that heralds a video call from my daughter and grandchildren in Australia, or the familiar voice of my son call, ‘Hi Mum, it’s me’, as I hear his key in the door.

And then there are those rare, yet wonderful days when the fog of dementia drifts away and the man I love emerges from the mist, laughing at a repeat of an old television show or the dogs’ playful antics. His smile, a reminder that true happiness is often found hiding in the smallest of places.

Happiness, like giggling at a solemn occasion when you know you shouldn’t, is contagious and when you share your joy, it comes right back to you.

When you feed the birds, they sing for you. Taking your dog out for the morning walk they love, reveals a beautiful sunrise that you would have missed otherwise, and babysitting for a friend gives you the pleasure of spending time with that small person.

That’s the wonderful thing about happiness, we can’t give it away because it’s not ours to give. That smile to a stranger, the helping hand to someone in need, and the word of encouragement to a friend, simply flow through us like a Mexican wave of love. Lighting the path for others, only to discover that it’s made our own journey brighter too.

Frank Sinatra sang, “When you’re smiling, the whole world smiles with you”, and it holds true, as does the saying that when we cry, we cry alone.

So if you meet someone without a smile, be sure to give them one of yours, there’s a good chance you’ll get it right back.