It may be that you’ve always known it. Or that you once did the research, and thoroughly educated yourself. In any case, now you regard yourself as an expert on the subject.
You’re probably wrong. It’s the areas in which you consider yourself most knowledgeable that there may be an Achilles’ heel.
Unbiased, in-depth research is a great tool to uncover what you don’t know about an industry, company or management team. Chances are good you’ll learn something of value that you assumed you were already smart enough to know.
True intelligence is knowing what you don’t know, and learning independently what you thought you already knew, but didn’t.