How come people high off pcp always lay on the ground, take their clothes off and say the world is gonna end?

I mean how can they do this drug? It makes you do things you would never do and takes full control of your mind. Like I saw this one guy one time take his clothes off and then he started walking back and forth in the middle of stalled rush hour traffic. He got down on the road and lay in the street right under this other mans car. Everyone was looking and this man couldn't drive he had to put the car in park cause this man high off pcp rolled under his car and stayed there. People thought the guy hit him with his car but he didn't. And why do people on pcp always start taking their clothes off talking about the world is going to end and they lay on the ground or always walk in the street by cars and they always get a creepy look in their eyes like their in a different world in a catatonic state. They repeat the same thing over and over again and if you ask them if they are alright they just repeat what you say and say it over and over stuck in one spot. Then when the drug wears off they never remember the weird stuff they did. It's some of the scariest things I've ever seen someone do Why is that?