What a question! Do you feel offended? I am sorry, I didn't intend to. The idea of bringing in the prison is to drive home a point> You know about prisons at various places. They are all outside you. But do you know there is a prison inside you? Yes, there is one in your mind. And do you know who is inside it? Who is imprisoned in the prison in your mind? You!
How is it possible? How can you be inside something that is inside you? As per the laws of Physics, you can't be. But in reality you can be? Don't you sometimes feel that you are unable to do something that you would like to. Your hands are free but you feel that they are tied. You feel that something or someone is holding you back. This means that you are not free. Not being free is the same as being in a prison.
There are several layers of prisons in your mind at different layers. You may be inside one sometimes. You can also be inside more than one prison at a time. However, most of us are bound inside a particular prison. This prison is the fear about what others would think if you do a particular thing. It is because you are inside this prison that often you are unable to do things which you would like to or which you ought to. Of course, it's in your hands to free yourself from this prison. the key to open these prison doors is a strong desire to free yourself from this fear.
The greatest prison people live in is the fear of what other people think. - David Icke