In Haruki Murakami's book "Blind Willow, Sleeping Woman," the author reflects on the nature of jealousy. He suggests that jealousy doesn't directly correlate with one's circumstances or the level of fortune they have encountered in life. Instead, it appears more as an insidious presence that develops within us, independent of our actual conditions. This perspective indicates that even those who seem fortunate can harbor feelings of jealousy, even if it isn't immediately apparent.

Murakami likens jealousy to a tumor that grows silently, uncontrollably, and without reason. It suggests that once jealousy takes hold, it becomes challenging to address it or to understand its origins fully. The metaphor highlights the relentless and often irrational nature of jealousy, emphasizing that it can manifest in anyone, regardless of their external situation, ultimately revealing a deeper complexity in human emotions.