We are very good (usually) at knowing which "side" of something we are on, be it a political opinion, sexual orientation, or a mark on the ground.
There is a subtle sense of being meaning to this, too: whether we are operating "above or below the belt," when dealing with another person. Above the belt means we are being fair, and also not being sexual. Below the belt means dirty, sexual, or mischevous.
When we think or sit down we "go back" in our heads or to the back sides of our body, putting more pressure or emphasis there. When talking we lean forward, and when walking we move forward. The line between front and back is a plane dividing the body from the side.
The symmetry line of the body dividing it left and right has an internal feeling counterpart. You know when the weight is more on one side of your body when walking, and you know the difference in feeling between using the left or right hand.
Likewise, there are two "worlds" to a lot of people, they clearly know when the situation is "A" and when the situation is "not A," and have different behavior patterns for each.
Many people live in many, many worlds, and are constantly evaluating which "world" they are in and which behavior pattern, and specifically, which single behavior, is right for the world they are currently "in."
Sometimes it is "cloudy" or confusing, so you spend time wondering which "world you are in," so you either have to wait for the internal weather to clear up so you know where you are and what to do, or you can take decisive action to 1) figure out what the situation is, or 2) try to get to the world you want to be in.