You don't realize what you do or use day to day until you no longer have it or have it working a 100%.
Take for example, the nose. A simple part of the face used for filtering the air we inhale and exhale every second of every minute or every hour of every day of our lives. Such a menial task really, you don't even do it consciously, it just does on its own. UNTIL you get a cold, or a sinus infection which fill your sinus passages with mucus and plugs your inner nostrils so much it gives you a numbingly painful headache and makes you just wish you could cut your head off nose first.
Another example of something we use everyday is the throat. We use our throat to talk, to hum, to sing, and all of this we do without thinking twice. Then you get a nasty sore throat, it gets raw and red, it swells, it itches, it burns and stings and you no longer have the ability to hum a tune, sing along to your favorite song or hit those high notes (or low notes) in church choir practice! You're entire voice changes, the sound of it alters, and you develop an inability to pronounce words without squeaking.
Want a third one, your thumb or pinky finger are something that you use to do everything, from holding a writing or eating utensil, picking up a book, paper, purse, backpack, opening a door, to washing or towel drying your hair. When one of these is sore, sprained, bruised, burned, broken, cut, or slammed in/under something ( i.e door or book) you will find it increasingly difficult and irritating to try and attempt any one of the menial tasks I have mentioned in line two of this paragraph. And you can forget about drumming your fingers on a desk, painting you nails evenly, or playing any musical instrument (besides the harmonica). Your world falls apart.
Its the little things in life that we take the most advantage of. We've got these things; a nose, a throat and fingers/thumbs so lets try to remember to appreciate everything they do for us, not neglect, forget or abuse them as we are all guilty of doing. For if you do, then you'll look like me, walking around the university student center with mucus coming out of your nose, trying to scratch your throat with your tongue and groaning at the same time with your pinky finger pulsing from pain because someone didn't hold a door for you.
Good night and remember, a healthy body is a happy body. So take care of yours.