Comment by bitwize

It could have from Dr. Benjamin Batmanghelidj, author of Your Body's Many Cries for Water in which he claims that chronic dehydration is the source of most disease (and thus water is the cure). The 8x8 was a minimum threshold for his water treatment protocol as I recall. According to Dr. Batmanghelidj, feeling thirsty was not reliable as an indicator of need for water, as dehydration was more likely to manifest as pain or hunger than a feeling of thirst. His methods have been called into question. however.