Compare your life to a tree if you must.
Call it just that. Say 'my life is a tree'
You start off with hundreds of leaves, thriving happily and carefree.
Then autumn comes and things begin to change.
Your leaves change one by one, and you can't help but do the same.
Then winter comes and again one by one the leaves begin falling to the ground.
They never find their way back up into that tree again, and begin to slowly disappear like the others.
All that's left is one leaf, and the frozen branch.
Until finally the leaves start coming back, and that one leaf is no longer alone.