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 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.
Top 50 things that baffle women about men
1. Why man flu is worse than a normal cold
2. Why they don't listen/their selective hearing
3. Their inability to multitask
4. How they can never find something, even when it's right in front of them
5. Why they say I've done the washing up 'for you' and think they are doing you a favour
6. Why they insist on leaving the toilet seat up
7. Their reluctance to use instructions when building/putting something together
8. Why they won't ask anyone for directions
9. Why they take days to do something women ask them to do
10. Why they snore so much, whatever position they are in
11. Why they insist on keeping cables, even when they have no idea what they are for
12. Why they find farting so funny
13. Why they insist on leaving dirty clothes on the floor or next to the wash basket
14. Why they think doing the dishes occasionally means they're contributing fairly to housework
15. Why they hog the remote control
16. How they can watch a football game, and then watch the highlights on Match of the Day that same night
17. Why they have to 'readjust' themselves in public
18. Their obsession with sex
19. How they can remember endless sports stats but forget important details such as birthdays etc
20. Why they need to have a 50-inch TV
21. Why they never want to show their emotions
22. Their obsession with boobs
23. Their obsession with gadgets
24. Why they can't understand why you're always right
25. Why they leave towels lying on the floor 'to dry'
26. Why men read on the toilet
27. Why they insist on trying to fix things themselves rather than calling in a professional
28. How they always manage to spend more money than you when it's their turn to do the food shop
29. Why they think women like being wolf-whistled at
30. Their obsession with being in charge of a barbecue
31. Why they don't ask the right questions
32. Why they have to show off in front of their friends
33. Why they leave the recycling next to the bin/box/sink instead of in it
34. Why they always have to be the one to drive, apart from when they want to drink
35. Lad culture and boys' nights out
36. Why they leave things to soak, and then declare they've 'done' the washing up
37. Why they stay up late watching YouTube/TV or playing computer games and then complain that they are too tired to go to work
38. 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
39. Why they insist on having their own chair/their own side of the sofa
40. Why they have to have a fast car
41. Their love of cars/engines and motorbikes
42. Why they have to watch something in HD
43. Why they put their arm around the back of the passenger seat when they are reversing
44. How the first thing they try on when clothes shopping is always the perfect fit
45. Why they refer to their favourite football team as 'we'
46. How they can happily spend so much time in a shed or garage
47. How they can claim to be a better cook than you, despite rarely cooking
48. Why they say they are going to call if they aren't
49. Why they get so competitive with their friends
50. Why they pretend they hate the cat / dog but everyone knows they love it the most.