The song "Sun on Sunday" by James Blunt explores themes of missed opportunities, selfishness, and the consequences of failing to acknowledge the pain of a loved one.

In the verses, the lyrics depict a situation in which the protagonist is aware of their loved one's emotional struggles ("tear," "empty smile") but chooses to ignore them or take them for granted. The mention of being a "thief, so selfishly" suggests that the protagonist has taken moments and experiences that should have been shared with their loved one and made them their own. This selfishness and lack of attentiveness is showcased by the line "And me the fool, you turn away," indicating that the loved one has become distant or withdrawn because of the protagonist's neglect.

The chorus highlights the protagonist's realization of their blindness and the regret they feel for not recognizing the loved one's pain sooner. They express a desire to make amends and fix the situation ("Is it too late now to fix you? Let me make it right"). The imagery of "no sun on Sunday" and "no reason for words to rhyme" represents a lack of joy and harmony in their relationship, emphasizing the gravity of the situation. The line "Cause if you're bleeding, so am I" highlights the deep connection between the protagonist and their loved one, suggesting that the protagonist feels their own pain when their loved one suffers.

The bridge section emphasizes the protagonist's devotion and fear of losing their loved one. They express that hurting their loved one would only cause them their own pain, and losing them would be worse than dying. It portrays the depth of love and the need for redemption in the relationship.

Overall, "Sun on Sunday" portrays a story of a relationship in which one person fails to acknowledge and support their loved one's emotional struggles, resulting in distance and potential damage to their bond. The song serves as a plea for forgiveness and a desire to make things right before it's too late.