Why is nitrogen narcosis called Raptures of the Deep

Nitrogen narcosis is called raptures of the deep from when famous scuba diver Jacques Cousteau first referred to it in this way. If you look at one of the meanings for rapture, it means: “A state or experience of being carried away by overwhelming emotion”. If you look at the symptoms of nitrogen narcosis, this could describe two feelings of nitrogen narcosis. These are euphoria and anxiety or terror!