go off the rails

The phrase "go off the rails" is an idiomatic expression that is often used to describe a situation or an individual's behavior when it becomes uncontrollable, chaotic, or deviates significantly from what is considered normal or expected. It originated from the literal meaning of a train going off its tracks or derailment, suggesting a loss of control or direction. It commonly implies a situation or a person experiencing a breakdown, malfunction, or a drastic change from a planned or established course.