Katie Byrne: At Christmas, it's the little things that send you over the edge, from the wonky tree to the in-laws
The world is divided into two types of people: those who giddily tune into Christmas FM on November 28 of each year; and those who lose the will to live when they hear Mariah Carey explaining that she doesn't want a lot for Christmas for the third time that day.
The latter group are often stereotyped as joyless, parsimonious 'bah humbugs', but UK-based clinical psychologist Linda Blair is of an entirely different opinion. She reckons they're just being mindful of their mental health.
Speaking to Sky News last week, Blair explained that shops playing Christmas songs repeatedly "might make us feel that we're trapped".
"It's a reminder that we have to buy presents, cater for people, organise celebrations," she said. "Some people will react to that by making impulse purchases, which the retailer likes. Others might just walk out of the shop. It's a risk."
Relentless Christmas music is all well and good if you're one of those jingle-jangling Christmas lovers who disappears down a candy-cane-coloured rabbit hole at the beginning of December and doesn't resurface until mid-January.
If, however, you're the type of person who doesn't actually "wish it could be Christmas everyday", well then the annual sonic assault of Wizzard, Wham!, Crosby and Sinatra can start to grate.
"Music goes right to our emotions immediately and it bypasses rationality," added Blair. "[So] Christmas music is likely to irritate people if it's played too loudly and too early."
Ask anyone about festive stress and they'll generally cite the two main triggers: money and family. Yet look back at Christmases past and you'll remember that it's the pebble in the shoe that tends to trip us up.
Sure, family rows and credit card max-outs are like death and taxes - certain - but it's the self-satisfied Michael Bublé earworms, the elusive Nigella Lawson recipe ingredients and the pine needles all over the floor that send us over the edge.
Here's five more insidious Christmas stressors to look out for...
Your place or mine?
Pre-marriage counsellors should ask couples just one question to find out if they can successfully negotiate the many compromises of modern marriage: whose family are you planning to spend Christmas with? The annual coin-toss is a bone of contention for many newly-weds, especially when they have to deal with guilt-tripping in-laws.
Mummy blogger envy
You were quite proud of the homemade paper doily angel ornaments hanging from your Christmas tree, that is until you made the mistake of looking at the DIY inventions of a Mummy Blogger who has constructed a life-sized nativity manger out of egg cartons and a fully-operational Santa's sleigh out of some old Fairy Liquid bottles. Next year, you tell yourself, next year...
Tree of strife
There are a few rules of thumb when putting up a Christmas tree: the tree should be positioned near a plug socket but away from radiators and open fires; there should be 100 fairy lights for each foot of tree; and, in the event of nuclear meltdown, every single human being within a five-foot radius should get the $@ out of your $@ing way! The business of buying, erecting and decorating a Christmas tree can send even the most Zen-like character around the bend, so if you don't know your way around a tree-topper, just steer clear. It'll be over soon.
There used to be a time when you could put a tea towel on a child's head and call him a shepherd. Nowadays, in the age of Pinterest, parents feel under a little more pressure to come bearing gifts of sequins, feathers and glitter when they create their child's nativity play costume. This arts and crafts extravaganza is no trouble at all for PTA martyrs; other parents will end up over the kitchen table until 2am, feeling like they forgot to do their homework.
You had just about got to grips with the average defrosting time of a turkey when your smug self-proclaimed 'foodie' friend announced that he's spreading his wings and cooking a 'turducken'. For food philistines, that's a deboned chicken stuffed into a deboned duck, stuffed into a deboned turkey. You would dearly like your friend to go and get stuffed but instead you try to outdo him by looking up the legal loopholes around eating ortolan.
We all scream for ice cream (and out of service ATMs)
Some enterprising techies have built an app that tells customers in the US if the ice cream machine at their local McDonald's is broken. It's one small step for man, one giant leap for Oreo McFlurry lovers. Perhaps the makers of Ice Check could now turn their attention to ATM machines, passport photo booths and shopping centre car parking spaces. They'd certainly have one loyal customer from this neck of the woods.