Lisa pulled in another shaky breath, and her eyes- spilling more tears- listlessly shifted down to her lap, where they didn't really look at anything. She was pushing what Sam had just said through every filter of logic left in her head. The words that stuck out were Believe me, I know.
"I know you..." Lisa looked up again, pinning Sam with her eyes. "I never met you before this place, but I know you... like I know Dean." Her voice was cracking. "Why... Why don't I remember??"