What Am I

What are they really thinking of you?

What am I to you?
A piano?
The sad song that helps you sleep?
A Cigarette?
Use me until I am nothing?
A old photograph?
I turn cripple and old yet the memory never fades or leaves.
A pair of glasses?
To help you see reality better.
A penny?
That you lose but find later on?
What am I?