Most scholars currently tend to see a biblical or “Gnostic” Sophia-Eve figure as the true identity of the enigmatic feminine self-revealer pronouncing the “I am” statements in Thunder: Perfect Mind (NHC VI,2). At an early stage of research, the similarities with the aretalogies of Isis, also framed as “I am” self-predications, were pointed out, but Isis has largely been left behind as a possible identity of Thunder, because of the latter’s ambiguous status, combining both elevated and lowly epithets (whore and matron, honored and despised, etc.). The present contribution reevaluates the Egyptian background of Thunder: Perfect Mind and considers the text as a demythologized, Platonic-Stoic, performative epiphany of a self-begotten, female, divine mind, similar in many respects to the Egyptian goddess Isis-Neith. Furthermore, it will be proposed that Thunder: Perfect Mind lies behind the common source of the self-predicative passage of On the Origins of the World (NHC II,5; XIII,2) and its parallel in the Hypostasis of the Archons (NHC II,4), likely mediated by the Gospel of Eve mentioned by Epiphanius of Salamis.