Dreams about preparing for an exam often reflect your feelings about your performance and readiness in real life. In your dream, the positive interaction with your professor and your acknowledgment of your understanding suggest that you have a solid foundation of knowledge, which aligns with the feedback you received from your professor about your performance.

The focus on having three days left to revise indicates a desire for preparation and improvement, pointing to your awareness of areas that need more attention. This aspect of your dream may also reflect your anxiety about your performance on the exam, particularly regarding the topic you struggled with.

Overall, this dream suggests that while you may have doubts about certain areas, your professor's praise indicates that you performed well overall. It shows your capability and the effort you've put in, which likely contributed to a positive outcome. Trust in the feedback you've received and remember that it's normal to have strengths and weaknesses. Use this experience to guide your future studies, focusing on the areas you found challenging.