Claims

Wittgenstein's phrase 'nothing is hidden' means nothing is metaphysically hidden—my subjective experiences are just as much public and accessible as physical facts about the world; the privacy of consciousness is only like the privacy of a ball hidden under a magician's cup, something that continued investigation could in principle fully reveal.

When Nagel claims we can never know what it is like to be a bat, he is not adding new philosophical content but merely stating the trivial fact that we are not bats and therefore cannot have the bat's perspective; the apparent mystery is a linguistic trick created by the word 'know' that creates the illusion of a metaphysical barrier where none exists.