“To teach is to learn twice.” – Joseph Joubert
You don’t need to be an expert to be a good teacher. In fact it often helps if you aren’t. Experts tend to gloss over a lot of details that beginners need to know. The reason for this is the experts are thinking at such a more advanced level that it never occurs to them to cover many things that seem very obvious.
An intermediate developer might be better at explaining a topic to a beginner than an expert.
You don’t need to be very much better than the next guy to be a good teacher.
You only need to be one step ahead to be able to explain the next step perfectly.
Zombie Code Kill 
Hey Kevin, great thought, I wish more people would realize this.
Being an expert or total beginner makes no difference when it comes to teaching. There are at least a few people I met in my life that had tremendous amounts of knowledge and they were terrible at transferring it (looking at you college teachers).
On the other hand, if you treat knowledge and teaching skills equally trough your career, I believe you can make great things happen.
People are scared to share their thoughts because they think they have nothing of value to share. But, in fact, the experience you have is always useful to someone.
Keep up the good work