My trusty WordWeb dictionary defines freedom as: "The condition of being free; the power to act or speak or think without externally imposed restraints". In other words, I am free if I am able to do whatever I want to do, say whatever I want to say, and think whatever I want to think. But, what is it that I want to do, and say, and think? I put it to you, the reader, that everyone, without exception, wants to do, say, and think, the things they deem will bring the greatest profit.
Let me explain a little bit more about the term, want to. It is easily confused with the term, wish to, but is significantly different. For example, thinking, "I wish I could play the piano", doesn't cost me anything. However, if that wish motivates me to sit down at the piano regularly enough to develop some skill, only then do I know, I want to play the piano. Again, wishing to tell your boss he's a fool, doesn't cost you anything, but articulating that thought is likely to cost you your job. If you want to keep your job, more than than telling your boss how you really feel, then you exercise "internal restraint" in order to pursue the most profitable course. In general, when a person is willing to meet the cost of something they wish for, the time and resources they invest become the evidence that they want it.
This duality of wishing and wanting is, I believe, well-illustrated by Jesus' struggle in the Garden of Gethsemane:
He went a little farther and fell on His face, and prayed, saying, “O My Father, if it is possible, let this cup pass from Me; nevertheless, not as I will, but as You will.”
-- Matthew 26:39
Jesus didn't wish to undergo the trials that were set before him, but he wanted to do his Father's will. We only know he wanted to do it, because he did it. In Jesus mind and heart, the net gain of walking the road to the cross, justified the cost of doing so.
What does it mean to be free? You are free at the very moment you realise: the things you do, are the things you want to do.
For example, when you tell a lie, your words are an investment in what you believe will bring you profit, regardless of what they actually bring you. Every lie is self-serving. I have heard people justify lying on the grounds that it has saved others' lives. In particular, it was put to me, "So, if you were living in Nazi Germany and were asked by a soldier whether you knew of the whereabouts of your Jewish neighbours, who were in fact, hiding in your cellar, you would have given them up?" I answered, a lie wouldn't be protecting my Jewish neighbours, but myself. Replying to the soldier, "Yes, I know where they are, but I don't want to tell you!", is a better option for my Jewish neighbours because, being the truth, it would be more convincing. However, it would be at the risk of my own life, which is why a lie about knowing their whereabouts would be self-serving.
It is so easy to imagine that circumstances and situations prevent us from doing what we know to be right and honourable and true. We get so used to behaving in particular ways that we lose sight of all the options. Truthfulness is like a genetic trait that can be lost over generations.