Once we've gotten our realities built, what do we do? Where do we go?
You wouldn't be reading this book if you didn't have some idea of some kind of VR experience to build. I encourage you to play and experiment. You can even try things that you've heard are bad (such as moving points of view).
When VR started exploding again, I was briefly somewhat disgruntled; most of the things that I'd done in the generation of VR before seemed to have been forgotten; people thought "VR UIs are new!". All the while VR academic literature is literally decades old, discussing perceptual effectiveness and VR UIs, just for one area of VR.
However, this is not a bad thing. If the people flooding into VR can come up with some fresh new idea, maybe that will be the "Killer App" that everyone is...