Forgetfulness is one of the Maladies of Lucifer. When he was priest of angels, he forgot to pray to God to protect him from deviating from the straight path. It is written in the Laws of God: "Be sure we shall test you with something of fear" and Lucifer was most afraid of Adam in his clay form.
When finally God commanded the angels "Let each one that holds Me for his Lord straightway do reverence to this earth" many that loves God bowed themselves but Lucifer with them that were of his mind disobeyed. They said: "O Lord, we are spirit and therefore it is not just that we should do reverence to this clay".
That was the day Lucifer fell from grace to grass. If he had remembered that he had just failed in his trial, he should have long stopped blaming his fall on the just judgment of God and repent. Again, he forgot he had no wings, and was not created with light like the angels, and yet was elevated and made Priest among angels. Who is he then, to question God what He should and should not do? I wonder.
Lucifer boasted that he would give God trouble on Judgement Day. O poor Lucifer! He has again forgotten that God has no need: It is man and Jinn that have need. If God wills, He could blot out present creation for another creation. Lucifer is indeed a confused man-Iblis.