This one night I was all stoned and it got me thinking, why does your mouth turn dry when you smoke weed? Then it hit me, people have been smoking weed with each other for 250,000 years right? So soon people evolved a mechanism that makes their mouth dry when they smoke-because it decreases chances of getting a disease through saliva they share when smoking a joint. The people who didn't get this mechanism died out from getting diseases from each other, and the cottonmouth people prospered...natural selection. Do you guys think I'm on to something?