This was not his intention, he would assure his correspondent. He really does not deserve the praise. Despite the narcissist's protestations, he feels much better now. The narcissist is a dilettante and a charlatan. He glosses over complicated subjects and situations in life.
False modesty is only one of a series of false behaviour patterns.
The narcissist is a pathological liar, either implicitly or explicitly. His whole existence is a derivative of a False Self, a deceitful invention and its reflections. With false modesty he seeks to implicate others in his mind games, to co-opt them, to force them to collaborate while making ultimate use of social conventions of conduct. The narcissist, above all, is a shrewd manipulator of human character and its fault lines. He will never admit to this.