In ancient pagan religions, it was common for a tribe to raise an animal that matched their totem. For example, if a tribe's totem was a (to plagarize "Clan of Cave Bear") a bear, they would raise a bear. Then at a festival would kill the bear, drink his blood and eat his flesh. It symbolized the flow of power from the God to the tribe. It also solidified their relationship, by making them one with their God.
This pagan ceremony has very powerful implications for superstitious, primitive, people. Eventually, it was adopted into Christianity, in a slightly more civilized format. Christians have an annual festival (Easter) marking the killing of their god incarnate (Jesus). They then symbolically drink his blood and eat his flesh.
Christianity has various communion rituals. Some perform communion regulary, or on special occasions. JW's have altered the communion ritual to an annual affair, and placed a slightly altered meaning on it.
They, of course, think that they are performing a unique and pure ritual. In reality, it is nothing of the sort.
If you miss a memorial, nothing will happen. The sky will not fall. However, scorning the memorial is the final sign to JWs that you are beyond hope.
They think that everyone who leaves them still knows in their heart that they have the truth. If you skip the memorial, you are dirt.
