I agree. Plumbing is physical and real - you can touch it and easily observe it. There is no abstraction to it, there are only a few driving concepts (like grav

I agree. Plumbing is physical and real - you can touch it and easily observe it. There is no abstraction to it, there are only a few driving concepts (like gravity.) The fact that plumbing has been around for 4700 years and 'computing' less than a century speaks to their inherent complexities.