This comes from Lewis Howe's book, The School of Greatness from 2015. One of the best books for self-development in my opinion. He is a big fan of the mentor-mentee arrangement for many reasons.
"What we need is someone who can not only help us set our original course but also constantly correct and guide us through the programs and adversity we will inevitably face." Lewis Howes
"A highly motivated person, when he or she has targeted a worthwhile goal, uses a coach or mentor the same way a missile uses the new guidance system (originally introduced in the 1991 Gulf War) to assist you in making adjustments and navigating difficult, uncertain, ever-changing terrain." Denis Waitley using an example relating new military technology to mentors