What is the origin of the idiom "set one's heart on something" and when to use it?

The idiom "set one's heart on something" can be traced back to the Middle English period. The word "set" in this context means to fix or focus, while "heart" refers to one's desires, emotions, and passionate inclinations. The phrase likely originated from the metaphorical association of the heart as the center of one's desires and aspirations. It is frequently used in conversations about personal growth, relationships, education, or career planning, where individuals express their deep emotional attachment and unwavering commitment to attaining a specific objective.