I like to assume it's in evidence in places where the author didn't intend it. Like that thing in... Countdown maybe? where his current consort says something cuttingly insightful about his mental state and he fries her - the fact that she was able to get that close at all, or that she was fearless enough of him to have been foolish enough to say it, you can easily attribute to him being unusually decent to her prior to that as a direct result of this, if you want.