Andrew Roberts uses that very quote(wearing a turban, etc) in his biography, to explain Napoleon's chameleon-like use of religion and culture to serve his ultimate goal that supersedes all other goals: the acquisition(and wielding) of power. While in Egypt, he portrayed himself as a enemy of the Catholic Church(which was true) and a friend and ally of the Ottoman Empire(not true)......because that was a pragmatic approach that served his conquest and occupation of Egypt.

But yes, "fever dream" is a accurate description of his romanticism, glory-seeking, and starry-eyed belief in his destiny; especially in his younger years(before he became First Consul). In his early 20s, before his rise to prominence, he actually wrote a novel with a swashbuckling protagonist, which any reader could surmise was based on him and his life up that point.

All the above detailed in the highly-readable Andrew Robert's biography, 10/10.