There is part of a system of thought that says every time you dwell on the thought of people or things you lose sight of your self.  It makes sense because thought, its being an ephemeral, comes in and goes on to another at the speed of lightening. Where is the you in that moment? A you that is essential, the you you want to find out about, go into at will and stay for longer than that lightening.  

     The habit of thinking about people and things disallows that, discourages that, waters down the ability.  Result?   One is spending hours of the day reaching out to an illusion, a passing evaluation, an ever changing object.  Time wasted.