Quite correct for this case 
But it is just a simple example to show how a process and its reversal are not “equally simple”.
It is worth noting though that there are, however, legal instances of what you describe, especially with land.
For example:
My earlier choice of the land registry was not accidental. Οnce the process is “completed” it is projected that a big percentage of the country will be unclaimed. This means that we will go from the “this is mine, this is yours” conflict/mess to the “good God, this is empty, GRAB IT!! before anyone else notices! I was here first!” 
This is where the really big knives will come out and “the real fun” will begin because a lot of people have land, use it, farm it, have built their houses on it, but they have no deeds (explanation below). So, they didn’t even bother with the expensive and complicated process of the land-registry. This means that most of the villages around my town are undeclared land. And let’s say that the locals will preserve the status quo, since they have lived with it for all their lives. What happens when outsiders (e.g. a contruction company) notices all those large empty swaths of land and decides “hey this is up for grabs, let’s screw those rural yokels over”.
If that happens then they will steal that land legally and they will get to keep it. Corporate lawyers ain’t no joke and the villagers are going to find that out the hard way.
A small explanation about the lack of deeds:
A lot of land is hereditory from a time where no deeds existed in the countryside. An actual example is a field my grandfather owned in his village. He had no deeds or any paperwork for it. Everyone in the village knew that it was his because it was passed down by his father or his grandfather, so it was his, case closed.
The boundaries are also hard to establish because the lack of deeds, means lack of topographical diagrams. Said field’s perimeter is literally established like that: “from that tree, to that stone, to that tree, to that corner of the hill, to that edge of the road, to that pole, to that stone aaaaand done!”.
Another small field with a few olive trees that my grandfather owned on a hilltop was actually lost like that. My grandfather is dead and my father was already unsure which tree and which rock we were supposed to take into account (rocks can move as time goes by or they can be moved by sneaky neighbours) and then the forest fire came and burned the surrounding trees and the olive trees and covered the ground in soot. The field is there “somewhere”, noone knows the edges, it is on a gnarly hillside that you can barely climb, so we gave up on it.
Now that my grandfather is dead and we - his descendants - no longer claim that land, whose is it?
The neighbours will say “thank you very much” to the sky and claim the land without a deed. Fourty years later some other grandfather will stand a kilometer downhill and point up to that distant hillside and say to their child “I have a field up there somewhere, from that tree to that rock, to that ledge, to that edge, to that three, to that rock, you’ll find it hoho” and so what was once my grandfather’s will pass to some other person and then to their children and then be lost again once that person dies and the neighbours will get it and so forth. Think of it as an odd land-recycing.
Knowledge of ownership in old/rural/unorganised places dies with the death of the people that know about it or with the change of the landscape. This is another factor that makes “simple and easy” even more ludicrous.
), but we don’t. EU and NATO are just pretending that we are all jolly good and having fun (while both sides are drowning in debt to buy more weapons and ships and submarines 
), but it is a bit too much to go around happily and pretend that somehow a casus belli fell from the sky in any case and place in the world.