After multiple attempts at trying to understand what a mitomane is from contextual Italian usage, I finally had to just look it up myself. From what I gathered, pre-Word of the Day investigating, a mitomane is an egotistical, self-centered person. Then I looked it up on Word Reference, my go-to Italian/English dictionary, and it said ‘mythomaniac.’ Well that was no help really.
Step 2 of my investigating: the Free Dictionary, an English dictionary. I mean, who has ever heard ‘mythomaniac’ used to describe someone? Not me. The definition of mythomania is as follows, ‘A compulsion to embroider the truth, engage in exaggeration, or tell lies.’ Not exactly a self-centered person, but one who just lies a whole bunch. Kind of like a myth can be an invented story, or a fantastical tale, a mythomaniac is one who makes sh*t up.
The word mitomane comes from the Greek word mythos, for a story or tale, and the Greek word mania, meaning malady or sickness.
Example:
‘Non ascoltare a quello che dice Mario, è un mitomane.’ – Do not listen to what Mario says, he is a mythomaniac (or he always lies).