Every sleeping soul of Ymirea ascends to the realm of Nod, therein it replenishes itself on spiritual and eternal essences. These visits to Nod are dreams.
Ymirean folk tend to take dreams seriously. It is believed that dreams are a worthy source of knowledge about oneself, the world and even the future.
Furthermore, dreams are real spiritual events, and a statement that "that was just a dream" to Ymireans denote the it was less than reality but more than a fancy.
The art of interpreting dreams.