The quote "I've been an idiot to think that real life could have a happy ending" from the book "Between the Lines" by Jodi Picoult expresses a sense of disillusionment. It suggests that the speaker has come to realize that life often does not conform to the idealized narratives we expect, where everything resolves perfectly. This sentiment reflects a broader theme in literature, where characters confront the harsh realities of life and the complexities of their emotions.

In "Between the Lines," Picoult explores the contrast between the expectations of a typical story and the unpredictability of real life. The character's acknowledgement of their naive beliefs highlights the struggle many face when dealing with difficult truths. Instead of a neatly wrapped conclusion, life presents challenges that can lead to growth and deeper understanding, regardless of whether one achieves a 'happy ending.'