 When babies are born, their bodies are over 80% water, but when we grow old and die, our bodies are reduced to 60% water. Similarly, when trees are young, they are very flexible due to how much water they have, but as they grow old, they become brittle and hard without as much water flowing through them. So, you want to stay young, feeling fresh and vibrant longer? Stop overdehydrating yourself and drink plenty of water.