It's eight, eight ounce glasses of water a day. Thats only 64 onces of water. (half a gallon) An eight ounce glass is one of the smaller juice glasses, not the larger 16-20 ounce dinner glasses. You are supposed to drink it throughout the day, not all at once.
Water does many things for you. Flushes your system, increases your metabolism, decreases the feeling of hunger, helps keep you regular, help cushion your joints, helps the immune system, helps circulation, and stablize blood pressure.
As noted about hunger, it's a known fact that some people mistake being thirsty for hunger and end up eating rather that what they should be doing. Drinking water.
Drinking eight, eight ounce glasses of water a day isn't that difficult. If you drink a 20 ounce bottle of watch during the morning hours, one in the afternoon hours, and one in the evening, thats 60 of the 64 ounces they say you should drink. That won't cause you to go to the bathroom 5 times an hour either.
Drinking eight of the larger glasses will.