The opening of the door indicates that the perspective is from the internal environment to the external environment. Opening the door inward means that you are ready to explore inward and have a journey of self discovery.
The door is the entrance and the boundary. Entering or leaving, we will enter a space with different situations and ideologies, because it leads us to different people and different atmospheres. Doors are checkpoints, guards, boundaries, barriers, and throats that pass from one space to another, from one experience and perspective to another.