If you'd like to go deeper into the subject of confusing shower water controls, I recommend the book The Design of Everyday Things, by Don Norman. The problem

If you'd like to go deeper into the subject of confusing shower water controls, I recommend the book The Design of Everyday Things, by Don Norman. The problem is not new. The study of human factors is fascinating. Don Norman is something of an authority on this subject. While the book is largely about faucets and doorhandles, it helped fuel my passion for building functional software.