Delusion is a pathological distortion of belief, a pathological reasoning and judgment. It has the following characteristics: 1. The content of the belief does not match the facts, and there is no objective reality basis, but the patient is convinced; 2. The content of the delusion involves the patient himself, and it always related to personal interests; 3. Delusions are personally unique; 4. The content of delusions is different due to cultural background and personal experience, but often has a strong time color.
Which one of the symptoms described below that can be judged as delusion?
Lili recently discovered that the things around her and the environment have changed and become unreal.The surroundings seem to be the background; the stage, the trees, and the houses seem to made of paper and lifeless.