I completely agree that marital drift happens. It's especially prevelant when a child comes along. You stop doing the things that made you a couple and you begin to lose the spouse/lover roll. CD it sounds like a lot of your issues and the gasoline and fire effect of yours and your W's issues colliding is very similar to my situation.
I think most people bail on the 'for worse' part. I was one who did see it possibly coming at some point. I had been through enough R and also watched those around me to realistically know that problems, sometimes big problems, often arise (I got M when I was 36). I remember before I got married I told my W that one of the things I really liked about us getting M is that we can work through any problems that arise. We were like that and I believed in it.
Of all the people I've talked to who initiated a D (mostly women) they pretty much went through the same pattern. Marital drift that slowly eroded the bonds that hold a couple together as a couple. How many people actually keep their eye on the ball?
I certainly didn't. But there was a whole string of intertwining things that eroded my R with my W. Many of them were issues we each brought into the M and not things that were created by our R.
The saddest part for me is I used to be very awake. I lost my center and the path I was on not long after I got M.
The even saddest part is when you hit a really low bottom in an R and you work your way back out, the height of how high you can bring it is often way past either persons expectations. I've heard this from many people who reconciled their M after some major obstacles - including affairs, alcoholism, abuse, etc...
MySitch Me-47 STBXW-41 D-5 S-8 ILYBNILWY-01/08 Want a D- 01/09 Physical Sep-01/10 D filed-06/10 Got 50% custody=09/11 Ride that wave!