In Twilight Saga Breaking Dawn - Part 2, after Bella is turned into a vampire, it's discovered she is a "shield", able to nullify other vampires' abilities.
Edward realises that this is why he couldn't read Bella's mind when she was human.
I didn't understand this, a human exhibiting part of their vampire talent, (albeit a small part).
Is this explained at all, is it all humans or is Bella a special case?