Don't compare yourself to other people too much -- what's normal for one person is not what's normal for the next!
I think it's a huge combination of your personality (resiliency appears to be hard-wired), your circumstances, the state of your marriage pre-D-Day, etc.
At four months out, we'd filed for D, but I was still hopeful he'd become the man I always thought he was. I didn't reach indifference until about 7 months post D-Day. But I have an advantage in that we didn't have kids together and no financial ties, so he's completely out of my life so I can move on.
Indifference is the goal. XWH now is just someone that I used to know. Me: BW, divorced, now fabulous and happy!
Married: 11 years, no kids
The greater danger for most of us lies not in setting our aim too high and falling short; but in setting our aim too low, and achieving our mark. -Michelangelo