Definition: Unreturnableness is a concept in psychology and philosophy that refers to the feeling of being unable or unwilling to return to something, especially when it has been lost. It can be described as a sense of being unable to bring back what one has lost due to circumstances beyond their control. Unreturnableness is often associated with loss, regret, and sadness, particularly in cases where an individual feels that they have not been able to retrieve the thing they had hoped to regain.