I do this a lot too, my shower provides a lovely drone to which I like to sing raga scales. On a different note, I can spend hours drawing little white squares with my mouse which line up with various things on my desktop, for example wallpaper, files, the edge of my screen etc. Oh and if i'm lucky one of the little squares will stay there after I release the button, then I get to line up another white square with it, and joy of joy when the two lines meet they disappear. If you don't know what I'm talking about you have never lived.