Randomness creates counter intuitively dense clusters. Humans tend to try and create order from chaos,it's how our minds work. Take the old IPods shuffle feature for example. It was completely random and yet people complained it played the same artist or song multiple times. They had to change it to "appear" more random because of human perception. Flip a coin 300 times there is a random possibility that heads Will show 200 times. Yes I know a coin is a 50% chance but same concept here. Complete randomness allows for having the same item many times because true randomnes cares not what came before.