Did you know that every day you shrink a little, too? You aren't as tall at the end of the day as you are at the beginning. That's because as the day goes on, water in the disks of the spine gets compressed (squeezed) due to gravity, making you just a tiny bit shorter. Don't worry, though. Once you get a good night's rest, your body recovers, and the next morning, you're standing tall again!