My best ideas come to me in the bathroom

I've heard that some people get their best ideas in the shower. I do, sometimes. I wonder why that is? Is it the sound of the water, white noise, masking out your other thoughts, allowing you to freely associate? Is it the warm water relaxing your muscles, removing stress? Is it because you're naked? I'll discount the last one since I know for certain some of my worst ideas (or shall we say, less smart?) occurred when I was naked. But, we won't go into that.

Where do we get our ideas from? Why do some stimuli bring out our creativity more than others? Does that stimuli create those ideas or are they already there, waiting to be called out?

I asked this towel, but it was trying to figure out a complex mathematical equation and didn't know anything about art. It was rather annoyed that I was interrupting its train of thought. So, I popped a couple flashes into its eyes and left it to it..