Character Analysis
Freud's Uncle Josef was one of five uncles who Freud knew throughout his life, but as he interprets his Dream of Uncle Josef (4.1.10-11), he mistakenly writes that he had "never had more than one uncle" (4.1.15). When Freud realizes his mistake, it's clear to him that his memories of Uncle Josef must be especially important.
As Freud explains, Uncle Josef was a man who had got himself mixed up in some shady financial dealings—"a transaction of a kind that is severely punished by the law"—and had reaped the legal consequences (4.1.15). Freud tells us that his father used to say that Uncle Josef "was not a bad man but only a simpleton" (4.1.15), and it's for this reason that the unfortunate fellow became a double-edged symbol in Freud's unconscious mind.
In Freud's Dream of Uncle Josef, dream-Josef appears as a simpleton figure and a criminal, and Freud's unconscious aligns him with Freud's colleagues "R." and "N.," respectively.
Since "R." and "N." were both Jewish men who had been passed over for prestigious professorships, and since Freud himself had recently been nominated for a prestigious professorship of his own, the dream—by depicting his colleagues as a simpleton and criminal like his Uncle Josef—let Freud believe that he might still be promoted while his fellow Jews had been passed over.