It must have been hereditary in my case. My Dad had a small collection, as far back as I can remember, and continued to accumulate more through the years. He was a "general collector", and pretty much bought whatever turned up in our rural Midwestern world. I started out much the same way, but underwent a transformation after buying my first old percussion halfstock. It was made in Cincinnati, Ohio, and was soon joined by a few more percussion rifles from here and there. I had soon traded all of the military muskets, Winchesters, and old foreign bolt-actions, for more American long rifles in various forms. Then came another transformation. A local friend of my Dad's told me he had a rifle that had been handed down through his family, and wanted me to take a look at it. It turned out to be a very nice percussion target rifle, with inlays and engraving. The makers name and address on the barrel, were those of an unknown gunmaker, in a town twelve miles from home. I tried my best to buy it, but never could. It did open my eyes to the fact that I lived in a state that had hundreds of gunmakers, but had never been researched by anyone. That was 45 plus years ago. There are now somewhere over 250 original antique guns, by Illinois makers, in my collection. Also a few Iowa-made guns, some Civil War guns with local connections, a dozen or so contemporary muzzle-loaders to hunt with, and a few of those "catridge guns" (they ain't safe....there are no breechplugs in them). I do have a very understanding wife, also.
