That one little leaf

I saw a solitary orange-brown leaf clinging to a lonely sapling —
And was sure that it would fall —
But it hung on even as its fellow leaves descended to the forest floor —
Even as Frost came out of hiding, his icy clutch bursting forth from the ground —
Even as Snow coated the land and blanketed it in her embrace, muffling sharp angles and casting a strange spell of silence throughout the trees.
Even as the icy wind blew and blustered, making the leaf shiver in the cold air.
That one little leaf hung on,
like a glowing ember amidst blackened coals,
like a torch in the midnight air,
it stood out and hung on, that one little leaf,
so determined to stand its ground.
And it was not until Spring came and exhaled her warm breath,
and the flowers bloomed,
did that one little leaf fall.
It floated gently down to the soft green grass,
and I thought I heard, when it finally let go,
a relieved breath let out,
and it almost sounded like a sigh of contentment.
And so now ask of that one little leaf —
Why did you hang on so long?
Were you simply determined to defy Nature's will?
Were you scared of what might come next?
Or maybe — just maybe — you were keeping that one little lonely sapling company through the harsh winter months, not wanting it to be alone, and so when new leaves finally budded and grew upon the branches of that lonely sapling, 
your duty had been fulfilled?
It seems that maybe you were only helping a friend survive through hardship —
staying long past what is due —
simply hanging on for that one lonely sapling —
like a true friend would.