How man flu is so much worse than a cold, their selective hearing - and why they won't ask anyone for directions are among the things that baffle women about men.
A poll of 2,000 women has revealed the top 50 things that they don't understand about the opposite sex, which also includes why men struggle to multi-task and their ability to snore so loudly - regardless of the position they are lying in.
Other women admit they struggle to get their heads around how a man can watch an entire game of football, but then also watch the highlights hours later and also why they refer to their favourite football team as 'we'.
Women also admit they are baffled by a man's obsession with sex, gadgets and boobs and why they find farting so funny.
A spokesman for online market researchers OnePoll, which commissioned the research, said: "Women are often said to be the more complicated sex, but it seems men still have their unexplainable behaviours and traits.
"Men and women are often very different - in the way they behave, communicate, express their emotions and deal with problems.
"But this can leave women struggling to understand why men do certain things.
"Man flu in particular is always a bone of contention, especially for couples. While women are known to struggle on while suffering a cold, men always seem to come down with a stronger bug that knocks them for six."
The study, of 2,000 women revealed that why blokes suffer from man flu instead of a regular cold is the most baffling things about the opposite sex, followed by their selective hearing.
A man's inability to multitask came third, with how they struggle to find something which is right in front of them and saying 'I've done the washing up... FOR YOU' close behind.
Other things which leave women flummoxed include why men insist on leaving the toilet seat up, their reluctance to use instructions or ask for directions and why they take days to do something after being asked.
Why they snore so much, whatever position they are in or wherever they fall asleep completed the top ten.
Other baffling habits men have include keeping miles of cables, even if they don't know what they are for, and how they can remember endless sporting dates and stats, but always forget birthdays and anniversaries.
The need to have a huge TV, why they read on the toilet and why they insist on struggling on trying to fix something themselves instead of calling in a professional also feature in the top 50.
A man's relationship with their friends also leaves women scratching their heads thanks to how competitive they are with each other, why they show off in front of them and the general 'lad' culture.
Why they want to have a fast car and their general love of cars, motorbikes and anything else with an engine are other baffling behaviours.
Top 50 things that baffle women about men- Why man flu is worse than a normal cold
- Why they don't listen/their selective hearing
- Their inability to multitask
- How they can never find something, even when it's right in front of them
- Why they say I've done the washing up 'for you' and think they are doing you a favour
- Why they insist on leaving the toilet seat up
- Their reluctance to use instructions when building/putting something together
- Why they won't ask anyone for directions
- Why they take days to do something women ask them to do
- Why they snore so much, whatever position they are in
- Why they insist on keeping cables, even when they have no idea what they are for
- Why they find farting so funny
- Why they insist on leaving dirty clothes on the floor or next to the wash basket
- Why they think doing the dishes occasionally means they're contributing fairly to housework
- Why they hog the remote control
- How they can watch a football game, and then watch the highlights on Match of the Day that same night
- Why they have to 'readjust' themselves in public
- Their obsession with sex
- How they can remember endless sports stats but forget important details such as birthdays etc
- Why they need to have a 50-inch TV
- Why they never want to show their emotions
- Their obsession with boobs
- Their obsession with gadgets
- Why they can't understand why you're always right
- Why they leave towels lying on the floor 'to dry'
- Why men read on the toilet
- Why they insist on trying to fix things themselves rather than calling in a professional
- How they always manage to spend more money than you when it's their turn to do the food shop
- Why they think women like being wolf-whistled at
- Their obsession with being in charge of a barbecue
- Why they don't ask the right questions
- Why they have to show off in front of their friends
- Why they leave the recycling next to the bin/box/sink instead of in it
- Why they always have to be the one to drive, apart from when they want to drink
- Lad culture and boys' nights out
- Why they leave things to soak, and then declare they've 'done' the washing up
- Why they stay up late watching YouTube/TV or playing computer games and then complain that they are too tired to go to work
- Why they get moody when their girlfriend wants to watch a girly TV show but then when the football is on there is no question about it
- Why they insist on having their own chair/their own side of the sofa
- Why they have to have a fast car
- Their love of cars/engines and motorbikes
- Why they have to watch something in HD
- Why they put their arm around the back of the passenger seat when they are reversing
- How the first thing they try on when clothes shopping is always the perfect fit
- Why they refer to their favourite football team as 'we'
- How they can happily spend so much time in a shed or garage
- How they can claim to be a better cook than you, despite rarely cooking
- Why they say they are going to call if they aren't
- Why they get so competitive with their friends
- Why they pretend they hate the cat / dog but everyone knows they love it the most.
