Yes, there're also adults who are groomed by abusers. Even if they're not directly abused, they're led to trust the abuser and overlook subtle but concerning behaviours. Parents can be manipulated to trust child abusers and leave children in their care.
Quite a lot of people are also lucky enough not to be exposed to abuse and won't understand the many forms abuse can take. It's one failing of a society to ignore the lives and plights of the disadvantaged (including the disabled, elderly) as people naturally socialise among similar people.