Answer:
What surrounds the world, yet dwells within a thimble?
My first is twice in apple but not once in tart. My second is in liver but not in heart. My third is in giant and also in ghost. Whole Iām best when I am roast.
Die without me, never thank me. Walk right through me, never feel me. Always watching, never speaking. Always lurking, never seen.
This thing runs but cannot walk, sometimes sings but never talks. Lacks arms, has hands; lacks a head but has a face.
What stays the same size no matter how much they weight?
You use it between your head and your toes, the more it works the thinner it grows.