When?

I stop to think every once in awhile. 
I wish I wouldn't. 
You wonder why I don't have many friends. 
Why I block everyone out. 
I can see it on your face. 
You never hear me speak, yet you hear my mumble. 
You watch me afara far, seeing if I'll even breath. 
You try to knock to see if anyone is home. 
Sorry, she moved a long time ago. 
No one knows where. 
She never comes outside anymore. 
Once in a while, you'll see her dog running in the grass. 
when was the last time anyone saw her face?