The following are five of the most common ways in which men misunderstand women, and some of the mistakes they make as a result.
1. Men don't know the difference between making a woman happy and attracting her. A lot of men believe that they will attract a woman by giving her what satisfies her in the moment, rather than doing what will demonstrate their character to her. Often these two things are in conflict. For example, a man will often tell a woman she looks beautiful, when the truth (which she knows) is that she is only looking decent. He will do this because he thinks that her momentary happiness is more important than her long-term ability to trust his opinion, and, by extension, him. Likewise, a man will often try to let a girl choose where to go for their date, because he wrongly believes that her enjoyment of the location is more important than her appreciation of his ability to be decisive and have a plan. These men don't realize that women are more interested in being with a man of character than frivolous things like always believing that they look pretty, or loving the restaurant where they enjoy a man's company. Men misunderstand this because they themselves are always seeking to be satisfied in the moment, and so they project that desire onto the women they date.
[Before everyone starts jumping down my throat for this one: I am well-aware that women love having an orgasm during sex. But if you "need" an orgasm in order to enjoy sex, ask yourself whether you'd prefer to be ravaged deeply by your man without an orgasm, or be given an orgasm by a guy who goes down on you for so long that he goes limp and loses interest in fucking you. Of course you want both, but both aren't always possible; and the point is that, when they aren't, men often choose poorly between the two options.]
3. Men think that you know you are hot. Many men feel powerless in the presence of a beautiful woman. Actually, it is more accurate to say that many men feel powerless in the presence of any woman in proportion to how much more beautiful than him she is. This is particularly true in younger men, but some men never grow out of it. Much of this feeling of powerlessness is due to the assumption that the woman knows that she is beautiful, and that therefore, they stand no chance of having her. (The rest is due to what I will explain in point number 5, below.) The truth, of course, is that a woman's confidence is absolutely uncorrelated with looks. Many beautiful women feel wildly insecure. However, a lot of men don't realize this. They are so stunned by beauty that they cannot see past it. A man like this might be too intimidated to approach or pursue a woman that he perceives as being out of his league due to her looks alone, when the truth is that the girl may be wishing that he'd approach her.
4. Men think that you mean what you say. Men are literal creatures. Natural selection has weeded out those of us who didn't have a mind for focusing on the facts and the facts alone, and getting the job done. The result is that, while we excel at those things, we suck pretty hard at reading between the lines, interpreting emotions, or understanding what is left unsaid. And the more modern culture tries to tell us that men and women are the same, the harder it is for us to understand that women don't suck at this as much as we do. Many men, therefore, believe that women are equally literal. These men believe that women mean what they say, and say everything that they mean - but this is simply not true. I got an e-mail just the other day from a reader who broke up with her boyfriend, not because she didn't like him anymore, but because she was hoping he would fight for the relationship. She (understandably) wanted to feel desired by him, so she tested him by ending the relationship. I can guarantee you that the boyfriend believed that she ended the relationship because she wanted the relationship to end. But the truth is that she was ending the relationship specifically and exclusively because she did not want the relationship to end. I can give similar examples in which women have asked for things they didn't want in the hope that the man wouldn't give them to her, or others in which a woman has said things she didn't believe only to incite a reaction in a man (or another woman). The point is that, when a man responds to you, he is responding to what you've said or done under the assumption that it is immediately and directly motivated by what you want to happen.
You'll notice that all of these misconceptions are due to projection, encouraged by the notion that men and women are the same - which is not anywhere near as similar as people think it is to men and women being equal. Anyway, keep these things in mind next time a guy does something confusing - chances are one of these will explain why.
2. Why Women Don't Know What Men Want
3. The Analogy Between Sex and Commitment