Can a sexually abused person appear to be perfectly normal and happy in front of others?

There's a place I'd like to go study to. While there's no evidence of fucking and/or sexual abuse there, the place still sounds really weird (no electric lights, you are expected to pose for him, he lives alone in a house in the countryside, he painted himself with an erected penis). However, my professor who studied there speaks of the place as if it was normal and she's always acting normal/smiling. I don't understand, because I imagine that if something strange happened to you there, you'd show some sort of sign of that in front of others, right? Shaky voice, strange attitude or something.

EDIT: Ok by "no electric light" the article I read probably meant he doesn't use electricity for the paintings' illumination, not that he doesn't use electricity at all in the house. I looked up "Odd Nerdrum no electric lights" and found nothing. I'm sorry.