It turns out that many men are completely clueless about their other half – including body shape, bra size and likes and dislikes, research has revealed. Even favourite perfume, date of birth and even eye colour are beyond many men.
While six out of 10 men claim to know their wife or girlfriend "very well", one in four have no idea what size dress she wears.
One in five doesn't know what size underwear to buy her, while a staggering 12 percent can't even remember her date of birth.
As a consequence, four in 10 couples have ended up falling out because the man has forgotten – or never asked – things he should really know.
"The results of this study are actually quite alarming as there are some basic details men really should know about their partner – in particular eye colour and natural hair colour," Gemma Mason, Marketing Manager for Superdrug, which conducted the survey of 1000 men to launch its new gift guide, said.
“Men can be forgiven for not knowing their partner's mobile telephone number off by heart but it's not difficult to take a look on their dressing table to see which perfume they're currently using."
The survey also revealed one in 10 men don't know what their partner's proper job title is, while a third can't remember the name of the school she went to.
Dates seem to cause major problems, because as well as forgetting when she was born, a further 35 percent don't even remember the date they met.
One in five blokes can't even name their partner's best friend, while the same percentage have no idea if their other half suffers from any allergies.
And while 15 percent of men always buy their women the wrong fragrance, a further 12 percent of women have returned a gift they didn't like because their partner clearly didn't pay any attention.
Shoe size, favourite clothes shop, and even their other half's natural hair colour also leave men stumped.
Blokes are also clueless when it comes to remembering their partner's mobile phone number, their middle name or their favourite song or movie.
Researchers found that despite their obvious lack of knowledge for their wife or girlfriend, almost two thirds claim they know their partner "very well".
Another 32 percent reckon they know them "quite well", but 48 percent admit they do need to make more effort to get to know the little details about their other half.
A sheepish three quarters say their wife or girlfriend would probably know all of the details about them if they were asked.
In general, 57 percent of guys admit men are just useless when it comes to remember everyday details about their partner.
"Christmas shouldn't be fraught because a woman receives a gift that makes her feel she's a stranger to her partner," Mason added.