there are lots of mind fcuk motivational posters that say when you see it you'll sh1t bricks
most of them are just going to waste your time - some are screamers
these aren't







and this is just a mind fcuk without the motivational writing around it (sorry for the lack of motivational writing)

stare at the shadow and the dancer will change direction
another little mind fcuk
http://youtube.com/watch?v=vzSRVgF501M