"(Lorimer Davidson) _When my opinion of Warren changed, I began asking him questions. And I found out that he had been a successful businessman at age sixteen. That he had filed his own income tax at age fourteen and every year since then. That he had had a number of small businesses.”_ *Income tax in simpler terms* It's like reporting to the government how much money you earned in a year and paying the required taxes on that income. This is usually done annually, and people typically file their taxes themselves or hire a professional to do it for them. In this case, Warren did it himself, without external help.