Hmmm... for me, I think it was a combination of things.One was my strong interest in colonial American history. Then I read a couple of von Mueller's books. I was a Journeyman Meatcutter at the time and my manager was into it. This was in the 70's. I started with a Fisher, model I don't remember, then moved up to a Garrett Groundhog ADS. My wife was against it so I eventually stopped (mid-80s). BUT, I recently retired and am getting back into it. I just bought a Garrett AT Pro though I still have the Groundhog with 6" and 12" coils. Recently I read that the Groundhog with 12" coil is still unbeaten for depth;.While I found quite a few coins back then, my most prized finds were a brass harness hook at the site of a long gone hotel in the Pine Barrens of S NJ, a U.S. Army Dragoon button that was government issue during the War of 1812, that I found on the grounds of a farmhouse in Media, PA that was built in the early 1700s, and a "two-pounder" cannonball I found at a site of a Revolutionary War skirmish known as the Battle of Signal Hill. So now I have an AT Pro but I have yet to take it out of the box.