Friendship when school ends is like the leaves of a tree:

Spring begins, trees filled with healthy green leaves,
As does friendships within the year.

Summer is the end.
You fill the leaves with hope,
You love these leaves,
You've always intended to keep contact,
But inevitably, Time does change.

And Autumn comes,
And these leaves that previously you had so dearly loved
Start to fade away.
You didn't intend on this,
You were so eager to keep in touch,
But people change, as do leaves.
The once vibrant green you had known and loved
Transform into an ugly unfamiliar brown,
As you desperately cling to these leaves,
Hoping for them to stay this beautiful green you once knew.
Soon you are just standing around these empty trees
That were once so familiar to you,
But now around you all these dead leaves.

Then it's Winter,
And these leaves slowly fade away
Behind blankets of white,
Never to be seen again.
And you just stand there, surrounded by nothingness.
Cold and alone.