'No Day Shall Erase You From the Memory of Time,' a phrase written by the Roman poet Virgil, is displayed on a wall at the 9/11 Memorial Museum.

(BOISE, IDAHO) For much of the past 25 years, each anniversary of the Sept. 11 attacks has arrived with signs and stickers reminding people to “never forget.”

I have always felt unsure about what those words mean. For those of us who were alive in 2001, forgetting the day itself is almost impossible.

Originally published on theconversation.com, part of the BLOX Digital Content Exchange.