The absence, and the following conflicts, worries and problems, arises because we use the present as a passage to the future, instrumentally.
Read for instance about the problem of time in Marcel Proust´s In Search of Lost Time, or in Thomas Mann´s Magic Mountain.
The Ego is a result of the past; without past there is no self-producing thought-activity.
Without the historical background, without this limitation, there is no such thinking.
But the thinking, which is a result of the past, can, as Kierkegaard said, not understand the present, since it only uses the present as a passage to the future.