Six times the Bible commands the Jewish people to "remember" either an event that took place or to observe something. All are in Deuteronomy except the first.
1. Remember the Sabbath and keep it holy (Ex 20:8)
2. Remember the day you received the word of God on Sinai (Dt 4:9-10)
3. Remember how the Jewish people tested God in the wilderness (Dt 9:7)
4. Remember the day of the Exodus (Dt 16:3)
5. Remember how Miriam gossiped about Moses (Dt 24:9), and
6. Remember how Amalek attacked a fledgling nation (Dt. 25:17-19)
Each one speaks of actions of Israelites in the wilderness. Each is a reminder for Jews through the millenia to learn lessons, save for the final one which recalls an action of an enemy people against an exhausted and untrained Israelite army. Perhaps the reason for this remembrance is to remind Jewish people to never forget that there are always anti-Semites in this world who want nothing less than to reduce or eliminate the Jewish people.
As a collective voice and source of strength in this post-Holocaust era, we can never allow that to take place again. We must always be alert, we must always remember.