Answer:
I am always in front of you, but you will never see me. What am I?
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
What loses its head in the morning and gets it back at night?
Upon me you can tread, though softly under cover. And I will take you places, that you have yet to discover. I'm high, and I'm low, though flat in the middle. And though a joy to the children, adults think of me little.
When it comes in, From sea to shore, Twenty paces you'll see, No less, no more.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?