The narrator questions a friend who challenges their perceptions, suggesting that the sun is red and the earth is not green. The narrator struggles to determine what is true and real in a world that is constantly changing.

Meaning of "How Can I Be Sure Of You" by Harry Nilsson

"How Can I Be Sure Of You" explores themes of uncertainty, questioning reality, and the ever-changing nature of the world. The friend's assertions challenge the narrator's understanding of the world, leading to a sense of confusion and doubt. The lyrics reflect the struggle to find stability and certainty in a world full of changing truths and perspectives. The conversation between the narrator and the friend highlights the idea that things are not always as they seem, emphasizing the need for questioning and critical thinking in navigating a constantly evolving reality.