Familiarity

Excuse me, do I know you?
You seem offly familiar...
No?
I could have sworn I knew you,
After all we've been acquainted for years!

Why this action is new, 
When did you start this?
The novelty quickly fades,
How-come you so suddenly are changing your ways?

Confusion sets in, 
Where did you go?
Tell me who this impostor is,
They claim to be you!

This cannot be,
I know who you are...
Am I now wrong?

Excuse me!
I thought you were someone I knew,
I thought you were familiar,
But I certainly do not know you.