Answer:
Never ahead, ever behind, yet flying swiftly past; for a child, I last forever; for an adult, I'm gone too fast. What am I?
There was a girl half my age when I was 12, now I am 66, how old is she?
What is harder to catch the faster you run?
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain; doing no harm, and feeling no pain. What am I?
I can be repeated but rarely in the same way. I can't be changed but can be rewritten. I can be passed down but should not be forgotten.
I tell people to be careful when handling boxes.