In actual fact, the Fishing Festival was not organized by Poseidon, but his daughter, the Mermaid Princess Herya. The young mermaid liked to play, but—just take a look, the figures who lived at the Poseidon Shrine, were they the kind to play around? They were either Sea Gods or relatives of Sea Gods. Even the guards, who worked at the Shrine, would be at least Bosses of Level 100 or above.
When NPCs reached levels of a certain height, the passing of time for them would be somewhat negligible. While the older generation stood firm by the notion 'the passing time is naught compared to that single moment of achieving great wisdom,' the energetic young Mermaid Princess was, of course, bored to death. She craved for companion, and thus secretly made use of her father's name to organize the Fishing Festival, so as to invite more players to play with her.