They seem to not realize that reality is by definition what we all exist in. Just because it's all in the head of an evil monster god doesn't mean it isn't real. Reality is a word to describe a condition, not an absurd abstract concept. The same goes for words like everybody. This word very rarely means everyone on Earth.
Words have context, use it.
Very few words have absolute, extreme definitions, and most of them are not abstract. Oh, forget it, you probably don't understand anyway.