After the battle ended, God gave Moses a strange commandment: not to celebrate, but to write. The Targum Pseudo-Jonathan reads it this way: "Write this memorial in the book of the elders that were of old, and these words in the hearing of Joshua, that blotting, I will blot out the memory of Amalek from under the heavens" (Exodus 17:14).
The Aramaic adds a remarkable detail — "the book of the elders that were of old." There is a record that predates Moses, an ancestral ledger stretching back to the patriarchs, and Amalek's name must be entered into it specifically so that it can one day be erased from it. The punishment is written into the same scroll as the sin.
Joshua must also hear the words spoken aloud, because he will be the one to carry the memory into the land. Forgetting would be the greater defeat. The Targum understands that evil persists partly through amnesia, and that remembrance is itself a form of resistance.
This is why the Torah commands, in Deuteronomy 25:17-19, to both remember what Amalek did and blot out his memory. The two are not contradictory. We remember in order to blot out. The takeaway: some wounds heal only when named, recorded, and then deliberately unmade.