Looks like both Jere and Wei Xian are right.
One, drinking a litre of water upon waking up in order to cleanse the bowel is an Indian therapy which is claimed to prevent serveral illnesses and keep the person healthy. This was recommended by Jere when he realised I have not been drinking much water in school.
On the other hand, Wei Xian's right too in the sense that excessive consumption of water (more then 1.5 litres) in a single intake can also have deterimental effects to the body. Read more on water intoxication.
I will probably start by drinking lesser than the recommended amount, say 500ml, and see how it goes. Yes, I am feeling rather unhealthy of late, probably due to the lack of excercise and hectic + stressful school life.
Btw, this reminded me of water parades in army days.. "Half water bottle drriiinnk up!!" Heh.