The Rules?

When it comes to relationships, there are few rules that are to be followed. One of them is that if you date one guy and you break up, you don´t start dating his friend. But what if you were never really officially in a relationship with the first guy, what if they are not close friends but rather acquaintances, what if... Can you break a rule without being the bitch who walks over people?
On an unrelated note - is it ok to make a relationship prejudice based on past experience with a specimen of the kind? Like if you dated let´s say a guy who liked fishing and he hurt you in the end(let´s say with a fish hook), can you make a rule of not dating fishermen? Well, of course you can do that, but is it ok? Then what do you do when you meet a cute and witty guy who asks you out, but also likes fishing?

The Rules?

Supposedly there are The Rules when it comes to dating. Being a weirdo, I have never really learned to obey them or to play other games in a relationship. (Maybe that is the reason why I am not in one.) But what if you start dating someone who sticks to them. Should you start behaving like these rules are the code of behaviour?
The silliest rule so far encountered is the three day rule - apparently if a guy likes a gal and they had an amazing date, he is still not supposed to call her until after 3 days. I don´t really get this need to show how much you DON´T care. And yes, I am aware that men are supposed to be the hunters and need the thrill and mystery and conquest, but it is just stupid to me. Either you like someone and want to know him/her better, see them again, or you don´t...
(And maybe this view on The Rules will result in me being a crazy cat lady.)