Lee Child. Jack Reacher, or is It worth dying (№ 318267)

Long experience of life in the district taught him that reality is what people think is reality. If no one mentions any event, it didn't happen. If nobody is talking about the man, it did not exist.
Reality was whatever people said it was. If no one ever mentioned an event, then it had never happened. If no one ever mentioned a person, then that person had never existed.