Maybe if Victoria Beckham made more of an effort to smile, she'd be seen as a happier person.

There was no shortage of proverbs growing up in our house. “Waste not, want not!” was a favourite with my father as he scooped in to eat what was left on your plate, often before you’d even finished.

“What doesn’t kill you makes you stronger, darling,” Mum would trill after horrible exams and fallings-out with friends.

But there was one that was used more than any other: “Smile and the world smiles with you. Cry and you cry alone.” I can still picture my grinning father issuing this infuriating nugget of wisdom when I was in the middle of an epic teenage strop. At the time, it made me want to punch his grinning face. But it stuck.

Twenty years later I smile a lot. I smile when I’m happy, I smile when I’m sad, I smile when I’m stressed and I smile when I’m with someone so boring I want to pull out my own teeth. I’ve even been told that I smile when I’m in the middle of crying. I don’t mean to - and often I’m not aware I’m doing it - it’s just my automatic response to almost any situation.

I remember once going to the doctors with what I now realise were signs of mild depression. As I blubbed my way through his box of floral Kleenex, describing my pitiful woes, my lovely GP looked at me and said: “Well, at least you’re still smiling.” I realised that I’d been smiling through my tears because I didn’t want him to think me too miserable or rude. Ridiculous.

Now, I realise there’s a name for Cheshire Cats like me: “fake smilers”. According to a survey published last week, Britons smile 26 times a day on average - that’s 9,490 smiles in a year and 446,030 smiles in adulthood from 18 to 65. But almost half of those smiles are false. We’re either concealing the fact that we feel down - or else pretending to be amused when we’re not.

Chat-show queen Fern Britton suffers from this affliction. In a recent interview she recalled a school friend saying to her, when she was very young: “Why are you smiling? You’re always smiling. Even when you’re talking, you’re smiling.”

The TV presenter, who has talked openly about her ongoing depression, says that she tried to wipe the smile off her face but couldn’t. “For a day or two I tried to go around like that [she pulls a long face]. But I can’t. My face is like a dolphin’s - it just smiles.”

Mine too, Fern! And very annoying it is too, apparently - not for the smiler but for the people who have to look at it all day. Smiles might be contagious but, used too often, they can be as appealing as a bad rash.

I read a story that US retail giant Walmart had to sell its German stores because business was poor. The reason? The American-trained staff smiled too much and the Germans found it irritating. They like their service to be brisk and impersonal, not all teeth and “Have a nice day”.

Indeed, a friend admitted that she didn’t particularly take to me when she first met me because I looked like “one of those annoying people who’s overly happy all the time”. She seemed to like me better when she realised that under the smile I was actually as miserable and grumpy as the rest.

A couple of years ago a drunk colleague at the work Christmas party asked me quite seriously (and viciously): “What the hell are you always smiling about? You can never trust anyone who smiles that much.”

I’m prepared to think that his question says as much about him as it did me, but did he have a point? Does a fixed grin make you look as suspicious as Tony Blair at the Chilcot Inquiry?

“Smiling is what you need to do to get along in life,” says psychotherapist Phillip Hodson. “It started off as a way of showing your teeth, which were your weapons. It then morphed in social society into a sign that ‘I may be armed but I’m not going to hurt you’. Now, a smile is disarming and polite and a way to bond with strangers.

“But smile too much all the time and you look as genuine as a double glazing salesman. The truth is that there isn’t always a lot to smile about and so people can be suspicious of those who do have a permanent grin on their face because it can seem dishonest. To quote Shakespeare’s evil Richard III: ‘Why, I can smile, and murder whiles I smile’.”

Although I can say, hand on heart, that I am no smiling assassin, I’ve lost count of the number of times people have asked suspiciously: “What are you smiling at?” When I say “nothing”, they look at me like I’m mad or stupid.

Once, I was so worried about what someone had said about my wonky teeth that I checked out my sub-standard smile in the mirror. I caught myself gazing at my gob and burst into a grin at how ridiculous I was being.

And it’s true what they say: smiling, even when you’re feeling glum, actually releases chemicals that make you feel happier. So my wonky smile stayed.

That said, smiles can be used for mischief too. It’s very interesting to see how confused people get when you smile at them on the street for absolutely no reason and there’s nothing more fun than trying to crack a sullen shop assistant by grinning like a mad woman.

That’s the thing about smiles: even the fake ones are good. They might irritate those around you, but they cheer me right up. - Daily Mail