The brain must be kept all the time hydrated. Even if the body lacks water, the body system will continue to supply water to the brain. As a result we need to drink sufficient water.Multinational companies now run water systems for 7 per cent of the world's population, and analysts say that figure could grow to 17 per cent by 2015. Private water management is estimated to be a $200 billion business, and the World Bank, which has encouraged governments to sell off their utilities to reduce public debt, projects it could be worth $1 trillion by 2021. The potential for profits is staggering: in May 2000 Fortune magazine predicted that water is about to become 'one of the world's great business opportunities', and that 'it promises to be to the 21st century what oil was to the 20th'.-John Louma, “Water Thieves," The Ecologist, Mar 04