My Secret Key

I have a key
I use it from time to time
To visit old friends
That have always been mine

Try as I may
I can never let them go
But keeping them around
Hurts me so

And so I have a key
I use it from time to time
I say 'hi' and I may cry
Hoping things will get better in time

And when I'm done
I put my key
In a secret place
No one knows but me