True, when you stand at a cliff and look down, you feel the urge to step forward, my theory as a climber is: Your eyes tell you it's flat so you can step forwa

True, when you stand at a cliff and look down, you feel the urge to step forward, my theory as a climber is: Your eyes tell you it's flat so you can step forward...but your sense of balance tell's you something different..brain is confused, you never have that feeling when your IN the wall.