The quote from Haruki Murakami's "Dance Dance Dance" highlights the complexities behind the act of dying. It suggests that while death may seem straightforward from an outside perspective, the reality is far more intricate. Just like an iceberg, where only a small part is visible above water, the reasons for a person's demise are often buried deep beneath the surface, making them difficult to comprehend. 

Furthermore, the passage emphasizes the profound depths of the human psyche. It asserts that only the individual truly understands their motivations, and even they may struggle to articulate them. This reflection on the darkness within the mind underscores the idea that personal struggles and emotions can remain hidden, complicating the understanding of one's actions, including the decision to end one's life.