Every Laravel developer learns the surface-level rule early – type-hint a class in a constructor, and Laravel “just gives it to you.” Most tutorials stop there, which is fine until you hit a case where it doesn’t work the way you expect — an interface that resolves to the wrong implementation, a singleton that isn’t actually shared, or a class that mysteriously fails to construct outside of a controller. Understanding what the container is actually doing removes the mystery. by Eric Van Johnson