Aussie No Rules

Whilst watching a game of AFL on t.v the other night, I have to say that the game is confusing to us newcomers after supporting the game of football and rugby. It's the scoring process that doesn't make sense; for example, why have four posts? surely the two big mothers in the middle are a large enough target to kick at from any distance! This is the only game that has 4 goal posts and you score 6 points for a goal but if you miss the target and get it between the outside posts you score 1 point and call it a 'behind', if you kick the ball and it hits the centre posts then bounces back into the oval you still get 1 point and call it a 'behind' I wonder if it's name has anything to do with the arses who can't kick straight.

One more observation, correct me if i'm wrong but surely the closer you can get to the posts the more chance you have of kicking between them, so why do the players take a 'mark' and instead of kick for goal they start running backwards away from the target! Maybe the game was invented by Irish descendents after a few pints of beer!