Kids accept where they are because they don't know the past. They know what they have; they know where they are.
We often live in the past a lot more than we probably realize.
Sometimes a scene works and acting is the easiest thing in the world and you don't have to do much of anything - just enjoy yourself and listen to the other actor. When it doesn't work, then every actor has different ways of dealing with the impasse. Sometimes you use memories from the past. Whatever. It depends from job to job.
