Bea, I think you are correct about the fact that some do know that something is wrong and others, just run and sweep everything under the rug and hope it will all go away. For example, when my xh was on his way out the door the final time, he said to me "I might be making the biggest mistake of my life, but I have got to do this right now". At the time, I thought he was just crazy, but the pieces of the puzzle are starting to fit together.
I do wonder just how long it will be before my xh's PA behavior appears in his current marriage to the ow. Right now, it appears that she goes along w/anything and everything that he wants to do. Unfortunately she's suffering from chemo right now and wonder just how this is all going to play out in the end. His mother was a clingy, needy woman who wanted someone to take care of her. Wonder if the wifey's situation will bring those memories back to the forefront of if he'll be the devoted husband that he wants everyone to think he is.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.