Answer:
Everyone has it and no one can lose it, what is it?
One by one we fall from heaven down into the depths of past, And our world is ever upturned so that yet some time we’ll last.
My first is in fish but no in snail. My second is in rabbit but no in tail. My third is in up but not in down. My fourth is in tiara but not in crown. My fifth is in tree you plainly see. My whole a food for you and me.
Two people are born at the same moment, but they don't have the same birthdays. How could this be?
What surrounds the world, yet dwells within a thimble?
You use it between your head and your toes, the more it works the thinner it grows.