Contrary to popular mythology, blood stains are easy to shift.
In cold water overnight, and then two cycles through the machine - works every time. She's practically an expert at that.
Memories, on the other hand, tend to stick around.
Causing death to dead things, you start to think it's nothing.
But stick a knife through the gut of someone who gasps for breath as it kills them,
even someone who betrayed you
tried to kill you
tried to kill your lover
you'll discover you're not as callous as you thought.
Death marks you.
And some stains don't shift.