Mutual Mentoring

Often, the relationship between mentor and mentee becomes one of mutual mentorship over time. But what if you went into the mentoring relationship with the understanding that it was a mutual mentorship, that each person is expecting to both give and receive knowledge and experience, offering each other the ability to grow where they desire to while harnessing and sharpening the strengths and talents they already possess? Would that taint the mentoring experience somehow, or (as I suspect) enhance it?