Answer:
The main difference between us and zombies
You can have it, and be at it, But it never lasts forever.
Tear one off and scratch my head, what once was red is black instead!
I question what lies above, and I’m shared with those you love. At my sound your hands will shake, and oft heard soon after wake. A card not found in a deck.
Often found in doctor's offices and pirate flags
I touch the Earth, I touch the sky, but if I touch you, you’ll likely die. What am I?