There are two kinds of experts, academic experts and practical experts. One is not better than the other, but they are very different and each offers very different value.
As its name conveys, the academic expert is just that -- academic. To become an academic expert takes years of studying. Academic experts are experts in how and what others have done. They use case studies and observation to understand a subject. Regardless if their expertise comes from quantitative or qualitative research, whenever they comment on a question they will reply with words like, "I have observed that..." or "in many cases..." or "the data shows."
The second type of expert is the practical expert. The practical expert gains his or her understanding for a subject by actually doing it. They didn't study what they did...they just did it. When they answer questions, they often reply with words like "in my experience."
Academic experts may not be good at doing what they are experts in themselves, but they are good at explaining the subject matter to others. They write books, teach courses and offer lessons and give steps others can follow.
Practical experts may be good at doing what they they know about, but they are not always good at explaining how or what they did in clear enough terms that others can can learn from or follow their lead. Listen to an interview with Richard Branson or Steve Jobs or Bill Gates and see if you can build a business based on the instructions they offer -- it's damn near impossible.
Unlike academic experts, practical experts didn't set out to become experts, they set out to solve a problem and gained expertise in the process. Ironically, most practical experts started with a total lack of experience in whatever they became an expert. Just the three examples I offered -- Branson, Jobs and Gates...as well as many other highly successful entrepreneurs...started their businesses when they were in their early 20's and knew very little about building a business let alone a huge corporation. And that was their advantage. Practical experts are unencumbered by what others have done or "the right way to do things." They were forced to figure things out themselves which is how they gained their practical expertise.
Constant observation is how an academic expert gains his or her expertise. They study those who have succeeded or failed. Practical experts, in contrast, try and fail more than they succeed, but their drive to never quit until they solve a problem is the defining factor that earns them their expert status. Anyone else would simply be someone who tried and trying alone doesn't make you an expert.
The academic expert is not is not better than the practical expert, we need both. The practical experts do the things that the academic experts can observe and translate into actionable lessons for others. But never has their been someone who was able to achieve great success by precisely following all the steps of any academic expert. It just wouldn't be practical. The practical experts are driven by their gut. They trust their feelings and they "read" the situation and are driven by finding a solution. And whether they like to admit it or not, the work of the academic experts gives the practical expert lots of information to assimilate and adapt where they deem fit. The difference is, the practical expert, as their name conveys, only takes or uses the parts that make sense them them.
Entrepreneurs must be practical experts. They needn't set out to be subject matter experts in what they do, they must set out to solve a problem or pursue some cause or purpose greater than themselves. With a clear understanding of Why they are setting out they will take the practical steps to blaze new paths that others, with some academic help, may follow suit.