Light

Light. Some times its treated As the bane of evil and the Darkness, others the source of live on all the Earth. Its also both a particle and a wave. It's also taken for granted (not granite). Yup, it's sorely missed when you don't have it. Like when you lose your flashlight, or when you can't see the screen on your computer. I know that a lot of people that have light at almost any time don't know what I'm talking about, but for those who do, bless you.