I am completely confused and befuddled by the mysteries of the male penis and sex drive, and not sure I'll ever really figure it out:

• A guy can get an erection for a girl he wants to be with.
  
• A guy can be attracted to a girl and want to sleep with her but be unable to have the erection.
  
• A guy can have an erection, even to the extent of being triggered by the presence of the girl, and yet have no desire to sleep with her?
  
• A guy can have an erection for and want to screw a girl that he feels nothing for. He might even dislike or hate her.
  

It all seems hopelessly disconnected and nonsensical to me....

As a female, it seems pretty cut and dried. If I want to be with someone, I tend to feel aroused. I don't think I've ever felt turned on by someone I didn't want. Sometimes I love a person and feel affection for them, but am not in the mood; however, I don't feel desire at that time. It's sort of either there or it isn't. How in the heck men can claim that women and women's desire is complicated is beyond me...