So you wear a wedding ring, but set no store by a lucky rabbit's foot. You're happy to walk under a ladder and are unfazed by black cats. Think you're not superstitious? Think again.
Author Max Cryer reckoned he wasn't all that superstitious, and then he started digging around to find out why humans do a lot of what we do.
He found an endless number of traditions and customs that defied explanation - until you factored in superstition. So he wrote a book about it.
"I'm no more superstitious than most - but I do confesses to a fondness for four-leaf clovers," he says.
"Many people tell you 'I'm not superstitious but ...' like there's something wrong with it.
"But they're curious to know where these things came from and they're curious to know do they work.
"And the answer is, of course they don't, but they're harmless, sometimes hilarious, and everyone has a couple of superstitions up their sleeve."
I'll drink to that
"Cheers." It's that sign of respect, celebration and support, with raised glasses, meetings of eyes, and that delicious "clink".
And it's all in the clink, which echoes back thousands of years when, Cryer says, people believed evil spirits would be driven away by "nasty, sharp noises".
"So people clink their glasses to clear the room of evil spirits, then drink their toast."
A defence for being loud on new year's eve
Raucous countdown. Mass toast. Slurred singing turning to shouts of "Happy New Year" sound right? Well it has to be, again to stop those nasty evil spirits bringing their negativity into the new year. We forgot to ask Cryer whether the inevitable Happy New Year snog with the person nearest is based on suspicion. We reckon pash away those demons, just in case.
Weddings are a minefield
If you've got no time for superstition but wear a wedding ring, you're a hapless hypocrite.
In ancient times people believed a vein of blood went from your wedding ring finger straight to your heart. A ring - the symbol of eternity because it has no beginning or end - on that finger would carry that love straight up the vein to your heart. Resulting study of the human body revealed no such vein.
Wedding superstitions are a book in themselves.
Brides didn't originally wear veils to cover their blushes, Cryer says. It was far more serious than that.
"In the days of tribal warfare if two men wanted the same woman and she said yes to one of them, at the ceremony she had to be covered from sight and surrounded by friends in case a marauder who also fancied here came down from the hills with a sword and abducted her," says Cryer.
Groomsmen and bridesmaids were part of the circle of protection. And you thought organising the bucks night or hens night was hard.
The groom also walks the bride out on his left arm so his right arm is free to grab his sword.
And that old shoe tied to the car when the bride and groom drive off? It carries the wisdom of its former owner.
Incidentally, don't wear one shoe around the house. Evil spirits really hate that - to the extent that someone in the family might die.
But if you put them under the bed with the soles facing up, you won't get cramps.
Isn't it just a birthday cake?
Nope. The cake honours the new moon and birth so it's traditionally moon-shaped.
But the candles are the business end. Their light goes up, honouring the moon. The smoke after you blow them out rises. That's why you make a wish - ancient belief was the wishes would be borne by the smoke up to the moon.
"Smoke and candles are also a custom in many religions," says Cryer.
"The word mass means flight so your prayers will be carried upward."
But back to the birthday cake. Why the pressure to blow out all the candles? More smoke.
Walking under ladders
Even the least superstitious of us still widely avoid walking under ladders.
It can be traced back to early Christianity and the holy trinity - the father, the son and the holy ghost. The trinity is a triangle, and a ladder leaning against a wall is a triangle, so a Christian person would not walk through that triangle because it would be seen as showing disrespect.
"What people haven't heard is the second half of the superstition, which says if you walk under a ladder keep walking and as soon as you see a dog, the spell will be broken," he says.
What's the connection between the trinity and the dog? "None at all," Cryer says. "But that's often the case with these things."
Aah-choo, bless you
It's almost automatic to say it when someone sneezes. Almost as impossible to stop as the sneeze itself.
"The ancients believed it was when you sneezed that your soul was being spurted out of your body and was going to escape," says Cryer.
"A 'bless you' was said to put the soul back into the person's body, and stop evil spirits coming into your body into the hole that was left empty when your mouth was open."
In the 1600s, when the Great Plague hit Europe, 'bless you' got deadly serious.
"Sneezing was a symptom that you might have the plague, so the 'bless you' meant 'we know you're going to die and we hope you are OK," says Cryer, cheerily.
Knock on wood
Those spirits again. Centuries ago, people were desperate things as well. It was believed a tree spirit lived in all trees, so if you tapped it, you were acknowledging the spirit in there. That spirit, having been tapped by you would help you in whatever problem you had.
No wonder tree-huggers seem such blessed-out, happy souls.
People thought black cats were witches in disguise. So strong was the belief that some people wouldn't discuss private business if a cat was in the room, fearing the cat would tell the witches.
Cats - black and otherwise - were also the victim of another strange superstition involving sickness.
"If somebody in your house is ill, wash their body with a sponge, pour the water over the cat, and the cat will run away and take the illness with it," Cryer laughs.
"If you don't have a cat, pluck a hair from the head of the sick person, put it in a sandwich and feed it to the dog, which will take on the illness."
Unlucky number 13 ... blame the scandinavians
In Norse mythology, 13 became unlucky when pagans worshipped a stack of gods who lived in Valhalla. One of the lead gods, Baldur had a party and invited 11 of the 12 other big-name gods.
He left Loki off the list. Big. Mistake. Loki rocked up uninvited, killed Baldur with a bow and arrow (a magic one obviously, you don't take down a god with a slingshot) and unleashed a thing called Ragnarok - the doom of the gods.
The fact only 12 people should have been at the party but 13 turned up meant that instead of a godawful hangover, Baldur was dead and 13 became very, very unlucky.
Unlucky 13 was reinforced when Jesus sat down for the last meal before Passover with his 12 disciples and as Cryer puts it "had a bad weekend soon after" when he was crucified.
Superstition surrounding 13 remains so powerful that in some areas of the UK no number 13 is allowed on a house in the street. In many buildings across the world there is no 13th floor, restaurants avoid having a table 13, and in Downing Street - where the British PM lives at Number 10, there is no number 13.
Or maybe they've set one up now, and filling it with fleeing politicians post-Brexit.
Garlic for vampires, but beware basil
Garlic has long been thought to protect against vampires, but Cryer discovered it's basil - "innocent, little, shiny green-leafed basil" that's the real worry.
Apparently if you sniff and eat the leaves a scorpion will grow inside you.
And if you don't want the scorpion to grow inside you put the basil leaves under a pot plant and the scorpion will grow there.
Garlic hasn't got bad press like that.