Acting is different from mental gymnastics. You try to discover as much about the character as you can, but a large area is mysterious.
I think all people are familiar with thinking about their death and trying to come to terms with the fact that we will, at some point, no longer exist. The loss of one's ego is very tough to reconcile with; you really have to do a lot of mental gymnastics to wrap your head around the idea of just not existing anymore. David Lowery