Astronauts who see Earth from orbit often say borders vanish. Most of what divides us only shows up close.

Some distinctions require proximity to exist. Lines between countries, between schools, between the two sides of a town are real in their effects and invisible from any distance. They are agreements, not features of the ground. That does not make them harmless, but it does mean they were made and can be unmade.

Pick one division you have inherited without examining it, the rival school, a neighbourhood you were told about, a group you do not mix with. Then spend an hour with somebody from the other side of it. The line usually gets noticeably thinner.