I think we can argue about whether or not it's fair to you that this happened when you didn't necessarily want the value to double. But you really do have double the wealth, there's no two ways about it.

Another analogy, is imagine you paint for a hobby. If the price of paint doubles it's not going to double the value of your paintings, you don't realize any of thos gains. You could argue that it's unfair, you didn't ask for the price to increase, you should be able to go to the store with the same amount of money as you used to and buy the paints. But that would be silly, it's not how the world works.

In general people understand that it's not owed to them that everything will continue to work the same way it used to. But for some reason when it comes to home ownership, people think they are buying the right to keep everything about their home and neighborhood exactly the same, even the things that are not just affecting them individually but have a big impact on the rest of the community (like who else can live nearby, how much property tax they should pay, etc.)