Hi wpainterw.
What you describe is a fruitless and mostly painful enterprise. And yet it's also completely human. Comparing ourselves to others, especially others who are more like we are than otherwise, is what we do. This despite the fact that we're missing important pieces of data when we make our comparisons.
The mind has an infinite number of ways to trick itself, and ruminating over a life that could have been or one that will never be is only one of them. It's like paying interest on a loan you'll never get. It's one of many ways to actually avoid living life. Worse still, it's a huge waste of time and energy for many people and, ultimately, a waste of a life.
When I first got sober about thirty years ago, I taught myself to expect that life is not supposed to work out the way I plan it to work out, which in turn opened me up to the belief that I didn't need to be in control of outcomes in life, and that whatever happens is not going to kill me, even when things seem to work against me.
The more I live in my head, the less time and energy I have to live my life as it is and as it will be.