The gun thing is an affection for firearms. Lots of people -- even some of us who have the gun thing -- find it a little odd. Why, of all the cool mechanical devices upon which we might have fixated -- musical instruments, old clocks, cameras, and so on -- did we pick guns? In a series of articles for various magazines and a book I’m writing under contract to Knopf, I’m trying to figure it out. I am spending a year traveling around the country, asking every shooter, dealer, collector, and hunter that I can find to explain his gun thing to me.