In the 11 years that I've been working in the mining industry, I have always had a coach. My career was anything except mediocre and I am grateful for the opportunities that I was given, to learn and to lead. Coaching is a deeply personal thing and it's important to get the right coach to help you on your journey. I watched a TED talk over the weekend and it cemented my belief that coaching works.
You need someone that will objectively guide you so that you can thrive in your career. That person points out what you need to work on to get where you need to be. They teach you new things, different things, things that you might possibly use every day for the rest of your life. It's not your destiny to be stuck in a job that you hate, or one that is so mundane that you can do it with your eyes closed. A coach can get you out of that, if you are willing to work on yourself.