"Sharing their clothes (even their bras?) with their friends."
There are some exceptions, but we would say that women tend to be more into style than men. You always want to have the perfect outfit and wear the latest fashions, but it takes some major funds to be on top of your fashion game. But a pro hack that a lot of us have caught on to is that if you share all your clothes with someone else, you will have double the wardrobe (genius, right?). Plus, it's not like there's anything weird in sharing clothes, they get washed after pretty much every use. And, yes, even bras can be shared - if you are the same size of course.
We're pretty sure that this one shouldn't confuse men as much as it does, though. Wouldn't you share a t-shirt or something with a friend if they needed one and were the same size? If not, maybe we just took the early lesson of "sharing is caring" more to heart!