because joints can be laced with the stuff

A "friend" got me with that one when I was 16. One of the worst nights of my life. Lost many friends who saw me in that state who had no idea I even smoked. Fairly certain it was "sherm"/"love boat", a PCP laced doob, due to the extreme tunnel vision and the fact that some jackass was able to convince me that if I rolled around in a (muddy) ditch the effects would stop. =/