Many people's lives are lived carelessly and frivolously, yet they treat everything in their hands as solid and real, unwilling to see it damaged or changed. That's probably how suffering is created.
When raindrops hit the pond water, they create musical notes on the surface. These notes are the circles formed by raindrops hitting the water surface.
Once a person develops feelings, they become incredibly insecure, afraid of separation, afraid of leaving, afraid that he will like someone else, afraid that my Sun Wukong will become someone else's Qitian Dasheng.