Wall

A wall and fence and prison will all represent a personal limitation. A fence is pretty easy to get past or jump over. A wall is a little harder to get through without a door or a window, However, it would only take a few minutes or hours to bust through most walls. A prison or jail is much harder to escape from. Because of this a fence will represent a small or weaker limitation. A wall will represent a stronger personal limitation. And a jail or prison will represent a personal limitation that has been holding us back for years.