I want you to consider the indignity of sitting on the train pondering the philosophy of linear functions of a single variable, not because you enjoy being reminded about being the kind of frail, helpless creature that needs hundreds of millions of microseconds to compute trivialities that any actual person would tell you come as naturally as breathing or mitosis, but because you want the website you're writing to have one of those adorable tag clouds and you need to tell the device what font sizes to use.