When relationships grow apart, we often hear people fall back on explanations like "We just got too busy," or "We don't live near each other anymore." But the reality is that the relationship ended because it was nothing more than a casual relationship that was supported by circumstance rather than deliberate choice.
Within these situational relationships, or Situationships, Desire is not a factor because the Quality Time is created by a circumstance such as work or school, and Desire to pursue more never develops. So when the circumstance that created the Situationship is no longer there, the relationship naturally grows apart.
Situationships still provide great value, meaning, and emotional benefit to our lives within the context of the circumstance, so it's important to enjoy them for what they are while taking the time to understand what propels some relationships forward, while others remain at a distance.