Fudayl ibn ‘Iyad (rahimahullaah) said:
If Iblees conquers the son of Adam with one of the three [things] he says, ‘I will not seek anything else from him’. (1) being fond of himself, (2) deeming his deeds to be plentiful, and (3) forgetfulness of his sins.
Source: Siyar ‘Alam al Nubala’ of Imaam ad-Dhahabee