Heartbreak is an overwhelming feeling of distress or a feeling of great sadness that everyone would get to experience at least once in their lives.
The way people react to this feeling differs. Some people take the approach of out of sight out of mind and take time out to deal with this soul crushing pain.
Others find themselves filling that void with comfort food while others do physical exercise to numb the feeling from their hearts.
Others shut down mentally and physically closing themselves off from the entire world while others blacken and somewhat develop stalkerish tendencies trying to get back together.
The path to healing from such excruciating pain differs but the end goal is the same. Zi Han was going through the same emotion. He was sitting in his mech in a daze overlooking the mountains.