Ask HN: What is product-market fit, and where do you find it?

Delving into the elusive concept of product-market fit – what precisely defines it, and where can one uncover it? Share your insights, experiences, and specific strategies for identifying and achieving product-market fit. Let's delve into the intricacies of aligning your product with the market's needs. Please refrain from generic responses; instead, provide concrete explanations with real-world examples.