They know what they want, its just not about rational desires but about feeling. A woman wants to FEEL... everything. They want a roller-coaster of emotion with ups and downs to excite them. You can't just be nice or mean all the time, as that is just stagnant and doesn't create the desired emotional swings. To create drama you need a guy who will fight with her and make her cry but then console and praise her and have make up sex, then turn around and make her furiously jealous only to come back to her with roses, something unpredictable like picking her up from the office for a surprise getaway. The man has to be strong (which can mean different things to different women, be it power, money, physicality), a solid foundation, but that can constantly push her buttons to feed her need for emotional stimulus. Just like the roller-coaster analogy, the "in-control" strong man that is grounded allows her to feel safe on the ride like having that safety bar around your waist. That way rationally she feels secure, while emotionally the rush of the ride provides all the right tingles. The challenge of course is keeping the rollercoaster ride going, as once you make a mistake and appear soft or stop feeding that stimulus, she'll likely start looking elsewhere for the thrills.