Batmanghelidj had a remarkable experience that led to his discovery about the effects of chronic water dehydration. While he was in prison, he was unexpectedly asked to treat prisoners despite not having any medical tools at his disposal. It was during this challenging situation that he began to notice some interesting things. He observed that many of the prisoners' ailments, which were typically treated with medicines, seemed to respond positively when they were given an adequate amount of water to treat their dehydration. This led him to suggest that perhaps a significant number of sicknesses could be effectively treated by simply prescribing water to address the underlying issue of dehydration. His insights have opened up a new perspective on healthcare and have the potential to revolutionize the way we approach the treatment of various diseases.