If you smoke real good weed or just get really baked, you will probably trip a little. SOme are more susceptible to it thank others. It looks like about 20% of people. Though its not straight shrooms or acid, yeah, you can see crazy shit or hear it. I actually closed my eyes and the fairies were whispering to me from wonderland, but I shooed them away and said I was dreaming. Then the faries said I was awake, and indeed I was. Awake, with my eyes closed, and stoned out of my fucking mind.