Grooberson not noticing Ghostbuster Spengler in town

Everyone was calling him the dirt farmer, he also didnt look to me like the type of guy who hangs out in the city all time. Even if the farm would be known as Spengler Farm, why would he have to connect it to Egon Spengler of Ghostbusters? Would you assume the King Farm in Arkansas would belong to Stephen King? He is a teacher, so would mostly know families with kids, but not an old farmer.
As I understood, Egon bought the farm 10 years before the movie and basically lived as hermit there doing his ghost hunting preparations. Meanwhile, Grooberson came some time between that and movies present to the town as teacher, because he actually wanted to investigate the earthquakes.