According to local tradition, the saint was ill-treated by pagans at nearby Mount Temple and fled in the direction of Annagh, which gives the site an unexpectedly human quality, a moment of vulnerability in a life more usually told through miracles and conversions.

The folklore surrounding the well was collected by P. Mulvey from the Christian Brothers School in Athlone and survives in the Schools' Collection, a vast archive of oral tradition gathered by Irish schoolchildren in the late 1930s. Mulvey's account situates the well within a broader narrative of Patrick's journey from Athleague to Tara, a route that required him to cross the Shannon at a place referred to as the Togher, an Irish word for a causeway or ford, typically a crossing point made passable through timber or stone laid across boggy or shallow ground. Miracles were said to have been worked at this crossing. The well at Annagh Mills then appears as a secondary site along that same path, marked by the saint's presence during what the tradition frames as a moment of persecution and escape.