What is the origin of the idiom "have one's head screwed on" and when to use it?
The idiom "have one's head screwed on" likely derives from the idea of securing or fastening something firmly in place. This phrase is employed when discussing individuals who consistently make wise decisions, approach problems with a level-headed perspective, or exhibit a strong sense of common sense. This idiom can be used in various contexts, such as personal relationships, professional settings, or general discussions about someone's character or abilities.