Personally I really reject the notion that an area of knowledge is strictly reserved only to those who are "officially", if you will, acknowledged as experts. On the one hand, there are many, many studies and bodies of research and so on once accepted that later have been proven wrong and even deceitful in purpose, so there go your "experts". And in the other hand there are countless examples of people sharing knowledge on topics they are "not experts" in. These are maybe more difficult to document, for obvious reasons, but at least at a personal level I've had enough of them to become keen on listening to personal anecdotes and "the wisdom of the village elders" if you get my meaning.