It is important to be able to give your mentoring partner feedback on how the relationship is progressing. It is also important for you to know how to receive feedback well, as this is the way you will grow and learn.
Few people are able to give feedback well; most people give primarily negative or primarily positive feedback. It is also difficult for many people to receive feedback. When they receive positive feedback, they are embarrassed and discredit it. When they receive negative feedback, most become defensive.
Good feedback is a gift. It is hard for anybody to improve without it. If we do not understand our strengths and developmental needs, it is hard to know how to develop and learn.