Answer:
I call the trees my home, yet I never go inside, and if I ever fall off the tree I will be surely be dead.
There's one in every deck of cards and in a famous movie
What can you never get rid of when you lose it?
Nothing specific, but more than a few. This many clustered, together will do.
Never ahead, ever behind, yet flying swiftly pastΝΎ For a child I last forever, for adults I'm gone too fast.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?