You think you are free; you are not.
You have no choice about what you are. You are just you; you can’t be anything else other than you yourself. You don’t really know how you came to be, or how you are going to end. You eat because you have to eat; you drink because you have to drink; you sleep because you have to sleep. You like someone because you have to like someone, for your own sake. You have no choice over these matters.
Worse, you don’t even have a choice over your own opinions. You have to agree with something, and you have no power to change what you want to agree with. You can’t choose what you like; you can’t choose what you don’t like. You can’t choose your hobbies, they choose you. You can’t choose your life, life chooses you. Even if sometimes it appears that you had made a conscious choice, it was actually not a choice; it was a merely a reflection of what you truly are.
What, then, is freedom? The only freedom you have is for the most insignificant things. You want to lift your arm? Yes you can! You have the freedom to do that, but what does it accomplish? As things grow complex, it becomes not within your freedom to do. You want to be someone you imagined yourself to be, but since you cannot be what you imaged, thus no freedom. Even if, in rare cases, that someone did become what they imaged themselves to be, they could not not be what they imaged, thus no freedom either.
Am I saying that everything is fate and we can do nothing to change it? No. I am saying that what we are we have no freedom to choose. I cannot not like thinking about these "useless" stuff because that’s what I am, and I cannot choose whether I should like this or not. Similarly, you have no choice over this either. You have no choice over whether or not you agree with what I am saying, and this is exactly what I am trying to convey.
There’s no freedom of mind, after all.