The quote reflects the idea that individuals strive to construct their own realities based on personal perceptions and experiences. However, it suggests that often, people overlook the true essence of the world around them, focusing instead on their subjective interpretations. This can lead to a disconnect where one's fabricated existence does not align with the complexities and surprises of actual reality.
Bellow implies that reality exists independently, whether it reveals joy or suffering, and that our imaginative efforts to create something 'better' may ultimately fail if they are not grounded in the truth of our environment. The authenticity of experiences, whether pleasant or painful, holds value and may even be more profound than our own concocted ideals.