Answer:
I am never quite what I appear to be. Straight-forward I seem, but it's only skin deep. For mystery most often lies beneath my simple speech. Sharpen your wits, open your eyes, look beyond my exteriors, read me backwards, forwards, upside down. Think and answer the question...
It happens when something has been cut with H2O.
They're up near the sky, on something very tall. Sometimes they die, only then do they fall.
I walked and walked and at last I got it. I didn't want it. So I stopped and looked for it. When I found it, I threw it away.
Without this, eating food and Steven Spielberg's career would be very different.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?