Joe David,

As Rabbi Dovid Gottlieb from Ohr Somayach writes, no culture in the history of the world has been able to fabricate a National Unforgettable and make it believed by future generations.

NU means an event on a national scale, of an unforgettable nature. All other fabrications are of events not involving an entire nation and/or something forgettable because it was not momentous in the first place (e.g."remember when you wore brown pants in 1st grade class") .

If national revelation can be forged, why does no religion besides Judaism claim it? obviously it would be advantageous for other faiths to claim so, but they are incapable.