I think recognizing when something has “run its course” often comes down to a feeling of stagnation or a lack of growth. It could be a relationship, a project, or even a personal goal. You might start noticing that the effort or energy being put in isn’t yielding the same kind of satisfaction or progress it once did. You may feel drained rather than inspired.
It’s often about listening to your instincts—when the challenges stop feeling like opportunities and just feel like obstacles, or when you start losing touch with why you started in the first place.