Remorse...

"Suchong, Of all the things I know, I know this. It is in your power to be a different man. What can Ryan take from us that we have not already sacrificed at the altar of discovery? They are children, Little Sisters, and yes, they will forget. But you and I won't… The memories of what we have done fade only with the dimming of all lights." (с)Brigid Tenenbaum.