Answer:
I can ruin your day, or darken your life. And while I'm expected, I'm never alright. I'm bad for business, and worse for your hair. Wherever I am, there's something not there.
I am mother and father, but never birth or nurse. I'm rarely still, but I never wander.
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
I am the heart that does not beat. If cut, I bleed without blood. I can fly, but have no wings. I can float, but have no fins. I can sing, but have no mouth.
Thousands lay up gold within this house. But no man made it. Spears past counting guard this house, but no man wards it.
People take me on walks and I run and have fun. What am I?