I have been lucky enough to be chosen by a number of people in the later part of my career to be 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 experiences where the mentee felt a connection strong enough to privately share their concerns and worries.
I believe in mentoring as an essential part of team-building in the junior (sometimes peer) colleague's education and growth. I've helped some move up the company and helped one to confirm their choice to leave - and most importantly why. They've gone on to have a correct next step and a secure direction for a great career.
I have found that mentoring is not about being an answer-machine - where inserting coffee plus a regular hour or two of discussion will vend a direct answer to their problem. Mentoring has been about listening and being a sounding board for their ideas and concerns. It has been about looking at and guiding the discussions from a different perspective, and in helping each of them move forward or sideways in the direction they choose. Whether in a small or a large decision, in simply setting a direction, or in wanting to understand their situation in context.
I every way it has been a pleasure to listen and to maybe help.