Your definition of what’s really important changes over time. The bare minimum set of people, stuff, and parts of the environment that you cannot be without. The baseline for you to be comfortable, or perhaps for you to even function.
You might not think about it often, but travelling brings it into sharp focus. The sudden need to decant your life into a couple of bags, complete with a weight limit. The paring-down process happens pretty quickly. What’s really, truly vital?
When I was seven or eight years old, the answer to that question was easy: Ghostbusters.