In the beginning of your relationship with a new man, its best to take things slow.  Think about how crazy it drives you when your not sure how a man feels about you.  It's the same for them.  The best way to act and feel is that you like him but your not 100% sold on him yet.  If he thinks you are 100% sold on him then he'll take you for granted and not be that bothered about your relationship. 

So thats why when your first dating a man its best to play the field a little.  If you can't see him for a night because you have another date then that will make him want to see you even more.  Plus if you have other options you won't be stuck at home wondering if he's going to call.  You won't be worried because you know that someone else will call you if he doesn't. 

Women often don't understand men and think that if they show a lot of interest the guy will be more attracted to them.  But often this comes off as desperation or neediness.  Guys want a woman is is hard to get.  Not a woman who is playing hard to get, but a woman who is genuinely hard to get.  That means someone who has other options and has a genuinely fun and enjoyable life.  Someone who isn't going to settle for the first guy that will take her. 

Understanding that is one of the keys to understanding men.