I'm a Gettysburg nut. Found that one question led to another and another, i.e., started picking-up biographies on Hancock, Sickles, Longstreet, Hood. Then started researching individual units in the battle, 1st. Minnesota, Iron Brigade, etc. After that I studied artillery projectiles and their effects. In awhile, began studying certain specific parts of the battle: Culp's Hill, McPherson's Ridge, The Railroad Cut, Wheatfield, Devil's Den, Little Round Top, Pickett's Charge, the Angle, etc. It just keeps growing and growing.
Someone once quoted as saying: "To understand every note in a symphony is to better comprehend its effect."