glitches?????????

hey all, well i dont get how people find glitches i mean does someone just run up to a random wall and start running back and forward and then just randomly slip under the map and they say WOW im under the map, i just dont get it, how do people find glitches, or even know where the glitches r, like the new zombie map, its already bin attacked by glitches, what is the dam point of it, one person out of the whole world gets to a very high level glitching, and uploads it and so everyone else does it, but all your going to be doing is wasting all your time tryin to get the number one spot its rediculous lol