Answer:
So cold, damp and dark this place. To stay you would refrain, yet those who occupy this place do never complain.
What is often returned, but never borrowed/
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
You throw me out when you want to use me and you take me in when you don't want to use me. Who am I?
Different lights do make me strange, thus into different sizes I will change
What never gets any wetter no matter how hard it rains?