It's set in the 1890s, according to the novelization, so around the same time as The Importance of Being Ernest, non? That was the association I was making, given the handbag comment. (the LINE is immaterial!!)

(I can picture Sammy reading Ernest in highschool, and deciding that he must have been left in the Impala in a handbag, or the like. Then Dean would make up a story supporting that. Ersomethin)