To be a mentor does not need to be officially agreed upon. For sure, it takes your time to be a mentor. The best benefit for a mentor is to confirm knowledge that we assume that we mastered. This post is based on a remarkable book written by Chad Fowler, The Passionate Programmer.
To find out whether you really know something, try teaching it to someone else [Chad Fowler].
This is the most significant benefit that you get as a mentor. Why is so that we need to recap the basics of how teaching works.
Here is Chad’s explanation. First, you need to be taught of as a topic. You can not start teaching without that precondition. You need input to process it and try to know the subject. But knowing the item is not the same as understanding their causes and ramifications. To get a more in-depth understanding, you create analogies. Doing that you try to understand why some similarities that you think should work but do not work. And wise versa, why some similarities that you believe should not work, work. When you start to teach that topic to someone else, you will get questions from students that may have never occurred to you. Doing that, you clean the dusty corners of your knowledge.
It is not needed to be an official mentor to someone. Today we have mentor social networks, like Stack overflow. Take for example, my friend Zeljko. He was mentoring for free on Stack Overflow about the Waitr tool. He gained a reputation as a Watir expert. Now, he has not to worry about his employment future. Or if you have a blog, you can start the AMA series, Ask Me Anything. The Watirmelon blog by Alister Scott is one such good example.
Mentors tend not to get laid off [Chad Fowler].
By doing mentoring, mentors create a network. For example, Zeljko was approached to be a speaker at several testing conferences.
To conclude, being a mentor is a job because it requires your time investment. But the benefits are much more significant than your investment.