My daughter asked me about freedom. I used the writings of Albert Camus (L' Etranger) to give her an example:
Can a prisoner in a prison feel free?
For some people, freedom is in the mind, and if their thoughts are free, they will never feel imprisoned.
Thus, the prisoner who escape through his thoughts will only feel imprisoned if, for example, a badly closed tap lets drops of water flow which, falling to the ground, make a rhythmic noise that prevents him from thinking.