JFK assassination

There seem to be so many people convinced the 'grass knoll' location played a part in the drama, that it is hard to let go of the conspiracy idea entirely. The naysayers to the conspiracy/cover up hypothesis appear to be either convinced there is nothing to it without solid reason, that, or they bring to the discussion flawed, unsubstantiated or outright suspect information to weight their case.
Have we been conditioned to believe there is something fishy here, or is there really enough hearsay and circumstantial evidence to warrant the suspicion? Many questions but few answers.