A landowner owned a large parcel of land that he divided into two equal parcels. Thirty years ago, the landowner deeded the eastern parcel to a purchaser by warranty deed, including an easement over the south 25 feet of the western parcel for access to the navigable river that ran along the westerly boundary of the western parcel. The landowner acknowledged the deed and easement, and the purchaser recorded the document. The recording officer maintains an alphabetical grantor-grantee index, but no tract index. The purchaser made no use of the easement until five years ago, one year after her neighbor had purchased the western parcel from the landowner. The neighbor had paid at least market value for the western parcel and was not aware of the purchaser's easement. The neighbor objected to the purchaser's use of the easement shortly after she began using it, but the purchaser paid no attention. The neighbor sues the purchaser to quiet his title and to restrain the purchaser from using the easement over the western parcel. The purchaser has reasonable access to a public highway on the easterly boundary of the eastern parcel. If the purchaser is successful, what is the likely reason