Delusions of grandeur can be thought of as less a detriment to one's mental state and more of a heightened sense of chosen reality, not dissimilar to the effect a day of popping the wrong pills or smoking the right cigarette or a swift nasal inhalation. I note this not as a professional on any level, and not based on the explanations of Dr. Google, but as someone who inflates her importance in this world as a means of survival. That's not the point, though; that's just my disclaimer.