A friend of mine had two bad experiences, first time in Swindon with a water pipe 24 years ago (not a bong they hasten to add), A Fripp and Eno record cover came to life and then they had to walk up and down the Old town unitl the effects wore off. Then in Manali in Himcachel Predesh in India (I haven't checked the spelling) with a chillum. This time they knew what the effect was and that it would wear off. The other 1000 times nothing like this. It is really hard writing in the third person.