Most investors, both institutional and individual, will find that the best way to own common stocks (shares') is through an index fund that charges minimal fees. Those following this path are sure to beat the net results (after fees and expenses) of the great majority of investment professionals.
There are all kinds of businesses that Charlie and I don't understand, but that doesn't cause us to stay up at night. It just means we go on to the next one, and that's what the individual investor should do.
In looking for people to hire, look for three qualities: integrity, intelligence and energy. And if they don't have the first, the other two will kill you.
You have to understand accounting and you have to understand the nuances of accounting. It's the language of business and it's an imperfect language, but unless you are willing to put in the effort to learn accounting - how to read and interpret financial statements - you really shouldn't select stocks yourself