What is the origin of the idiom "go spare" and when to use it?

The origin of the phrase "go spare" is not definitively documented, but it is believed to have originated in British English during the mid-20th century. The exact source or etymology is unclear. However, the phrase likely draws on the idea of someone becoming so intensely frustrated or agitated that they go beyond the limits of what is considered normal or expected behavior. It can be used to depict responses to personal disappointments, perceived injustices, or when individuals feel overwhelmed by stress or pressure.