Since you'll never understand it, no explanation will make sense to you. But I'll try anyway. What I do affects my neighbors because many things do not stop at

Since you'll never understand it, no explanation will make sense to you. But I'll try anyway. What I do affects my neighbors because many things do not stop at the property border. This can include smells, visual impact, water runoff, sound, chemical waste, and risk of fire. For example, if I decided to run a dry cleaning business at home then my neighbor might be affected by the additional street traffic (a shared resource), the noise of customers coming in and out, and the smell of chemicals. Plus, I dispose of the waste chemicals by pouring them into the ground, which seeps into my neighbors' well water. They might not like that. If I decide to start a fertilizer factory (I'll call it 'West Fertilizer Company II'), then my neighbors might be worried about explosions destroying their home. If I decide to raise cattle, and build a waste lagoon on the edge of my property then my neighbors might be concerned about the smell and the possibility of overflow, both as waste and erosion. If I decide to test my air raid siren collection at 3am then I suspect that my neighbors might have a problem. There are several ways to handle this. One is as an easement system. When you purchase your land, you do not have complete say over what happens on the land. For example, there may be a right-of-way which allows people to cross your land in order to get to the beach. You must also allow people to use the sidewalk, and you are required to keep it clear. So you can think of your neighbors as having certain easement rights, which you agreed to when you purchased the land. Just like the airport has purchased the air rights above a certain height, in properties near the airport, your neighbors also have acquired certain rights. For an example, from http://www.englandairpark.org/sites/default/files/docs/Brochure%20-%20Avigation%20Easement%20Program.pdf http://www.englandairpark.org/sites/default/files/docs/Broch... : > The Avigation Easement grants a right-of-way for the free and unobstructed flight and passage of aircraft through the airspace above, over and across the surface of the property, together with the right to cause such noise, vibration, odors, vapors, particulates, smoke, dust, or other effects as may be inherent in the operation of aircraft, and for the use of said airspace by aircraft for approaching, landing upon, taking off from, maneuvering about or operating on the Alexandria International Airport. As you can see, some of these rights can be on the market, but others are illiquid. However, there are a lot of things which can transgress the property lines. It's too many to enumerate explicitly. Rather than having billions of bilateral neighbor agreements, with billions of opportunities for loopholes, and the need to upgrade those agreements over time as problems arise, we have a unified code and legal framework which handles most of them.