Well all women are different so it's hard to pick a single thing that all men need to know about women. I know alot of people will probably say that men should understand that women are delicate creatures and need to be taken care or something that kind of makes women sound a little weaker than they actually are but I disagree with that.
Personally I believe the one thing that men should know about women is that they are our equal. There's nothing weak about them and they need to be treated with respect as well as love and care.
If anything, women may even be superior to men, after all they're the only ones that can give birth, and it's been scientifically proven that a female egg can fertilize another so it's not like as if the world will end if men should seize to exist.
Women are equal to men and they should be treated as equals, in our homes, schools and work places. That to me is what men need to understand about women.
I hope this helps.
There is no general thing to be understood about a woman. Understanding is an art, occurring every day and wants to be lived moment by moment.
If the man understands and knows himself very well than he will be able to understand the woman he is connected with. If the woman understands herself well too, they can be a creative and co-creative couple.
For the sake of a lasting love relationship, of course women and men need to be open and time to understand each other. But sometimes, women don't want to keep explaining what they want from men.
Many women hope men can understand what they mean without having to say it directly. As reported by Allwomenstalk, this is something that women want men to understand without having to be told first.