The answer is a delusion.
Robert is exhibiting delusion due to his depressive disorder. A delusion is a kind or characteristically a symptom of mental disorder which made a person having a distinctive belief or impression that is positively maintained despite being opposed by what is generally accepted as reality or logical argument just like what Robert portrays.
Heavily influenced by the introduction of foreign cultures, cuisines, languages, genetics, religions, philosophies, etc.
Answer:
d!
Thought I'd add it on here too. :)
