Me too - or was. I got tired of the work schedule and changed industries.
Maybe you guys are much more talented than we are, but I've never met an actor who could honestly separate himself/herself from his/her character completely (I'm not even sure what that would mean. If I don't expect professional actors to do it, I certainly can expect it from my players.
You make it sound so radical. It's not "separating yourself completely from your character." It's understanding that your character does not necessarily have access to all the information that you the actor/player have. You don't need to be Meryl Streep to wrap your head around that.