I've been lucky enough to be chosen by a number of people in the later part of my career as one of their mentors. Whether it's been to initially help them with a specific problem they had which led to a longer term relationship, or whether the relationship just happened and grew.
They were humbling experience where the mentee felt a connection enough to privately share their concerns and worries.
I believe mentoring as an essential part of team building and junior (and sometimes peer) colleague education and improvement. I have found that mentoring is not about being an answer-machine, where inserting coffee and hour of two of discussion will vend a direct answer to their problem.
I'm consistently amazed at the myopia of the cookie-cutter perfection expectations from management process dreamed up by email-committee's who will never have to follow or adhere to the "rules" that flood the corporate world. This shortfall of the "rules" insights stifle the creativity that the corporates demands in pursuit of profit, and by their enforcement create the conundrums that many of my mentees have come to me with.
These are never a simple solutions, but a long series of small course corrections made by them as a result of our conversations that brings the good outcomes - and a quick thank you in return makes so much difference, making the whole effort worthwhile.