According to the teaching of Thomas Aquinas, the answer is based on the radical distinction in essence between time (tempus), in which we creatures live, and eternity (aeternitas), which belongs to God alone. While our human existence is characterized by a constant succession—a continual flow in which the present moment immediately becomes the past and the future does not yet exist—God’s eternity is not an infinitely long timeline, but a “standing now” (nunc stans). In this absolute existence, God does not possess His life in fragments, but in a perfect, simultaneous fullness (tota simul), which is why nothing escapes Him and nothing still needs to come.
It necessarily follows from this that God does not need memory in the human sense, for memory presupposes that something has passed and is absent, something that must be mentally retrieved. However, since God stands exalted above the flow of time, He loses nothing to the past. What we humans regard as historically past or future lies open and unhidden before His divine gaze as pure, immediate presence. He views the entire history of creation not as someone who traverses a landscape step by step, but as one who, from a high summit, perceives the whole path—beginning, middle, and end—in a single, all-encompassing glance.