... you start dreaming in html.
You know how you can right-click on a web page to see the source code? Last night I had a dream in which I saw the world that way. I could look around my ordinary surroundings, and see the html behind all of it that determined the size, color, and shape of things, how far apart they were from each other, and so on. It was kind of fascinating and kind of... disturbing.
I don't know what browser my brain was, though.