 They do not change. I always use the ridiculous example of the law of gravity. If you don't like it, it's okay, but 100% of the time it works. 100% of the time you jump out the window, you're going to hit the sidewalk. It's not an old-fashioned way of looking at things. It just is the freaking law of gravity. And 100% of the time that you spend more than you make, it's not sustainable.