Why can't those who don't understand liberty understand liberty?
I have a hypothesis.
There are those who are able to use liberty when it is available. They don't put any thought into it; it is just there, or it's not.
They are like the people who can use fire as a simple tool, as long as someone else provides it. (Including by manufacturing lighters.)
There are then those who can see how liberty could be increased, and hunger for it when it is violated. They appreciate it, even if they can't really think outside the box. They often see nothing wrong with violating the liberty of people they don't care for.
They are like those who can usually build their own fire when they need one, and then use it as a tool, but don't understand the physical conditions which result in fire well enough to figure out how to make one if the familiar methods aren't available to them. They are probably a bit irrationally afraid of fire.
Then there are those who deeply understand liberty. They know what it is, at an instinctive level. They understand the implications of having it as well as those of having it denied. They can find ways to create liberty where none exists. They know people only get as much liberty as they respect in others, regardless of how they personally feel about those other people.
These are like the people who understand fire. They understand what it is and why it is necessary, and hidden ways it is used that most people never notice. They understand the chemical and physical processes which cause fire, and due to this understanding, can think of new ways to make fire if none of the known methods are available, and they can dream up new ways to use fire once they've got it.
So, trying to explain liberty to some people is like trying to show a dog how to make a fire with flint and steel, and then use that fire to smelt iron, make tiles, and cook a meal. They simply can't understand. Do they have a hole in their mind where liberty should be? I don't know. Is there a way to help them understand, anyway? I'm not sure.