Everything and nothing is relevant. [But he goes to answer the more direct questions.]

Nothing made Sammy special. He simply was. The man with the snake, similarly, was special. No clear reasoning, no indication, just... a stroke of luck, fate, misfortune, a hand striking down at a solitary being and placing an unseen mark upon them.

What Charlie saw... I can't say. Oh, I can sense things like he can, but I never quite got the story from him. That little detail is lost on me. He simply knew, like I know. I expect.