"Gaining" and "losing" things are an unavoidable part of life for everyone. You feel joy, you feel disappointment, and it repeats. And that's how you learn how to handle your feelings. Dissapointment and loneliness are necessary emotions. Because of loneliness, people muster courage... and reach out to a new world. Doing that is like reaching out as a baby does, and expands its small world.
From episode 33, time 19:26.