Is there such thing as true freedom? (My thought is that only in an anarchist society there would be-meaning that even the slightest rule or law would detain one's freedom to do as one pleases...)

Even in a world without laws or social rules, our ability to do exactly as we please would, presumably, be constrained by by all sorts of things--our own abilities, the actions of other people, gravity. (This won't be true, of course, if we could somehow adjust our desires so that we didn't want anything that we were constrained from having. But if we can do this, we might as easily do this in the world with laws.) In fact, the existence of rules and laws seems actually to allow us to do more of what we want. For example, the enforced convention that we drive on the right side of the road (in the US) allows us more efficiently and effectively to move about and do many of the things we want to do, even if it prohibits us from driving however we like with legal impunity. So, I doubt that anarchy would give us the "true freedom" you seek. But I wonder how much value we really place on "freedom" in this sense.