A better example might be why we build stairs with a standard riser height and tread run. If you've ever accidentally tripped on an unusual or non-standard stair, you already know this.
Users don't need to think about how to use them; they are ubiquitous and familiar, and therefore intuitive and automatic.
If every set of stairs (or, worse, if every stair in a set) was radically different, every time you approached some stairs you would have to think carefully about how to use them so you don't fall.
Users don't need to think about how to use them; they are ubiquitous and familiar, and therefore intuitive and automatic.
If every set of stairs (or, worse, if every stair in a set) was radically different, every time you approached some stairs you would have to think carefully about how to use them so you don't fall.