Book excerpt: For two decades, pastor and leadership consultant Matt Keller has worked with hundreds of influencers, and he has learned that the greatest enhancer or greatest limiter to a person’s success is whether someone is teachable. In The Key to Everything, Keller shows how teachability isn’t something that some people are born with and others aren’t. It is a characteristic that can be learned and grown. In fact, the only way to succeed in life is to possess teachability in an ever-increasing fashion, and The Key to Everything reveals how to do just that.