I just re-read the thread and wanted to add a few thoughts that I had. I had an ideal in my head about what the perfect relationship was for me, but there were times I got exactly what I wanted and I ran in the opposite direction. I would lust after other people's possessions and lives, but never realizing that the grass is always greener when you are on the other side of the fence looking in.
It is something I struggle tremendously with as a WH and a SA. I think there is something inherently embedded in my psyche (and maybe the psyche of men and women who choose to step out of on their partner) that I am always searching for validation, always thinking that whatever I have is perfect until something "happens" (I make a decision because I am bored, looking for justification, etc.) then I am looking for the next perfect thing.
I just realized that cheating and doing whatever to get ahead was acceptable in certain situations in my family. Our choices are our choices, but they were shaped by someone and some things.