What is the origin of the idiom "clean up one's act" and when to use it?

The idiom "clean up one's act" originated from theater in the 1800s, when messy improvised acts were common. As plays became more professional, directors demanded neat appearances, strict adherence to scripts, and tighter control over performances. They told disordered actors to clean up their acts by disciplining behavior and appearances to meet professional standards through preparation and conformity. It is generally used when an individual must overhaul existing conduct, attitudes, or lifestyle choices that are subpar or problematic through committed self-improvement and discipline.