More generally, every computer eventually has to interact with the outside world, which is global and mutable. Human mind have a much easier time dealing with t

More generally, every computer eventually has to interact with the outside world, which is global and mutable. Human mind have a much easier time dealing with things which are as immutable as possible. For instance, a physical law like the Newton's law of gravity is immutable. The variables within it are mutable, but there's only a few of them -- they would be local in a function that computed the force of gravity. Without such laws, it would be very difficult to reason about physics.