Do We Really Need Eight Glasses a Day? 

no i don't think so becasue now study shows that everything we eat or drink has some water in it.

You should drink water at least everyday. People who don't drink water daily tend to be more thirsty. Craving a lot of sweets, desserts, and candy means you're dehydrated. Plus if you don't drink water you can faint from dehydration (I've experienced fainting from being dehydrated and I drink 2 tall glasses of water a day).