Ross Ashby says: That homo has a brain no more entitles him to assume he knows how he thinks than possession of a liver entitles him to assume that he knows how he metabolises. (http://www.rossashby.info/aphorisms.html)

WARNING: PROJECTIVE GEOMETRY MAY PUT HOLES IN YOUR BRAIN.  YOUR MIND MIGHT LEAK OUT - IF YOU WANT YOUR MIND IN YOUR BRAIN STOP READING NOW. Okay, here is a geometric exercise that I find very interesting (for some context about WHY it is interesting, look here). It is, however, more complicated than the previous one...

my fingers are tapping to an unknown rhythm a sightless pattern just below consciousness feeding somewhere in the background of my eyes it swirls, dives, escalates, tumbles and words - my God, words! appear mysteries profuse my skin invisible knives punctuating reality letting the dreams out all the while tap tap tap   and more: you, unquietly reaching impossibly leeching, receiving  growing dreams of my dreams with another...