Ok so im just messin around on superflat creative, right? and its night time on easy so, yea. lots of mobs. anyway im just flyin around then i realize something. all the mobs are facin one way. not moving. so i check it out with mah diamond sword. i go up to a zombie and hit him with my sword. but not even a flinch. no damage, even. this freaked me out. but after a bit they "regained consciousness". what happened there? please answer!