When your high with someone and you're having a conversation with that person, people outside the conversation who are sober cant understand? I think its because when your stoned your brain processing half of the things that it normally does, thus making your brain works twice as fast....and seriously...smoke with a group of friends but have one person be sober and you will see how much they get lost in your high conversations!!
Also...post things here that you think other people dont know about being high! :D