I'm fairly certain I could finish my personal gaming project, create the ultimate campaign and possibly even end world hunger if these efforts didn't require a set of rules.
Not that I advocate complete chaos (though incomplete chaos is vaguely appealing) but I have a lot of trouble creating rules and than writing them down.
See, I'm not a huge fan of rules. I acknowledge the need for them and a totally freeform game would get out of control too fast but generally I view the rules of most RPGs are a necessary evil. I feel that, 9 times out of 10, the rules slow the game down. And slow, for me, is bad. I'll slow down the atmosphere to create tension but I hate when the rules slow down our (the players and my) ability to do things.
Let's take initiative for example. Man I dislike the very concept of initiative. As if, in a fight between a bunch of your boys and those guys from down the street doesn't all occur at roughly the same time. Christian of Destination Unknown explains kind of how I feel. I usually just wing it based on the flow of the moment and common sense*. Problem is you can't write a game that way. Well, you could but it'd be a tough sell.
Unless a rule is fun in and of itself and/or invokes a feeling appropriate to the genre I'm playing in, all I want the rules to do is get out of my way so I can run my game. Its an attitude that has served me well for 33 years, yet doesn't translate well to a published game.
In the end, I may just use the rules that annoy me the least and assume that whoever plays my game is just going to chuck most of them anyway. Just like I would.