 They then pass through Eunoe to have the memories of their good deeds in life strengthened.Upon completing his or her sentence in Purgatory, a soul is washed in the rivers Lethe and Eunoe (in that order) by Matilda.It is unclear who Matilda was in real life, but, nonetheless, her function is to cause the penitent to forget his or her sins (now that these sins have been purged) and then sip from the waters of Eunoe so that the soul may enter heaven full of the strength of his or her life's good deeds.