Hanged Man‘s illustration arises from at least three myths from different times and places about a man or god who sacrifices a body part or body function to the gods in exchange for psychic/magic/spiritual gifts and abilities, by hanging himself on a tree for three days. One of the myths is Odin sacrificing an eye.
So Hanged Man is awareness, realization, psychic experience, psychic development, sacrifice, insight, seeing things upside down.