What this rule checks
Your Rahu is in the 8th house. Rahu is about ambition and desire. The 8th house is about change, hidden things and shared money. Source: Phaladeepika, chapter 8 (a classic text), slokas 25 to 27. Notes beyond the classic text are the author's own modern reading. Classic texts describe this placement harshly. Read it as a tendency, not a verdict.