"Are you getting enough sleep? Are you sure? This engaging, fact-packed look at the science of sleep will make you think again. For something that all humans (and most animals) do for hours every night, sleep is not as well understood as you might think. Scientists don't even really know why we sleep! But they know it's important. And this book takes readers through just why it's so important, what your body's doing while you're dreaming, what happens...