any repetative song like that can become wearing at some point. Hall of the mountain king, flight of the bumblebee, fast repetative riffs that you work on and slowly bring the tempo up on as you get the mechanics down can be trying on everyone else other than the musician. Just ask anyone who\'s ever lived with one.
Hell, I remember hearing about how tim drove people nuts when writing merge because he was just sitting in the back of the van playing the riff over and over again for a few hours while he wrote the lyrics.