If you rap your knuckles against a window jamb or door, if you
brush your leg against a bed or desk, if you catch your foot in a curled-
up corner of a rug, or strike a toe against a desk or chair, go back and
repeat the sequence. 
	You will find yourself surprised how far off course you were to
hit that window jamb, that door, that chair.  Get back on course and do it
again.  How can you pilot a spacecraft if you can't find your way around
your own apartment?
		-- William S. Burroughs