If you would like to enter a small space from a larger space and other people are trying to exit the smaller space to the larger space, it makes more sense to let the people exit the smaller space before you enter the smaller space because it makes space in the smaller space for you.
Also, I’m pregnant, jerk. Let me off the damn elevator before you push past me to get in. Next time, I hit EVERY FLOOR BUTTON just to slow you down.