Well, sweet questioner, it is because I have learned to enjoy the sound of silence. Most days, the inside of my head looks quite similar to the picture above. The silences in my life are so heavily outweighed by the noise of everydayness that I never introduce a single extra sound to my already cacophony saturated life.
This used to be a point of contention in my marriage. Read: it drove my hubbie crazy that I would turn off the radio every time I got in the car or silence the ipod when I walked into the kitchen. 8 years later we've called a truce and he lets me live with as much silence as possible and every so often I'll let him listen to music while I'm in the room (at a very very low volume - this works because I'm practically deaf).
But mostly I choose silence because, if every moment is stuffed with sound, when would I have time to listen?
And speaking of listening, here is a conversation you might enjoy overhearing. #2 looked at me just like this and asked:
L: Mom, why do leopards have tails?
M: Well perhaps to help them balance or to wrap around tree branches or something (don't ask where I came up with the tree branch thing -- I figure if they're gonna ask me crazy questions they're gonna have to go with it)
L: No mom, it's to help them jump on leopard trampolines.
Of course! Why didn't I think of that?