I talk about the mind's eye zooming in and out here. I talk about creating larger and larger infinities here. I feel like the two are related.
The mind's eye sees a "set" of stuff in front of it. Zooming out involves seeing a larger set of stuff, including the spot where our mind's eye used to be.
Of course, since our mind's eye is now someplace new, it also seems like this creates the potential for an even more zoomed back position which would see in front of it our current mind's eye.
Hence, it seems like there's always something behind us that we can't see.