Answer:
When young, I am sweet in the sun. When middle-aged, I make you gay. When old, I am valued more than ever. What am I?
We applaud if you perform well.
To you, rude would I never be, though I flag my tongue for all to see. What am I?
I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?
Die without me, never thank me. Walk right through me, never feel me. Always watching, never speaking. Always lurking, never seen. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?