Arthur, welcom aboard.

Without getting into the realm of diagnosing I will suggest this has nothing to do with narcissism. Rather this is being delusional. There are numerous reasons for this as it occurs with multipe mental illnesses. For example, I am bipolar. When I have had episodes in the past I have had a mentality that I can do anything. Some might describe this as my having had a god-complex. At any rate it was a delusion.