Charles is about to complete his military service ; his behavior becomes more and more bizarre : when he fights in a boxing match , he loses because "he felt he was not able to punch his opponent" ; in the barrack-room ,he suddenly feels too modest to get out of bed before his mates ; and,mainly ,he does not want to marry his fiancee anymore.His barrack buddy ,Gaston, tries to cure him ,by making drink a potion made by his future brother-in-law, a chemist ,and by entrusting him to a (female) shrink .But the more he tries , the more he feels he's not a man anymore .