Commonalities in Hardship

I've had multiple conversations about this recently and I think I've been particularly interest because of my scholarly interest in resilience (and related constructs such as hardiness, psychological capital, etc.) as well as in finding benefits from having experienced stressful and/or traumatic experiences, so I figured I'd write about it here and see what you guys thought...

Basically, I was talking to a fellow grad student that I like a lot and we were talking about how we both tend to really like and be friends with other people who have had something terrible happen to them or have had to overcome something. Those are the types of people we feel most comfortable relating to and sharing problems with and those that just "get" us. It was then easy for us to generate examples of people that we didn't like - some of them mutually disliked grad students - who have everything handed to them. Those most despised frequently try to explain that they do have problems, like when they spent their monthly allowance too quickly or didn't get to go to both South Africa and Ireland (just one). They oftentimes tell this to people like me and my friend who struggle to pay for everything on our own and have for the better part of a decade.

So my question is this: Are we (some of us) attracted to others who have overcome something because they are simply similar to us (like is attracted to like, birds of a feather flock together), which is a well-established psychology principle? Or is it that the experience of overcoming something fundamentally alters your personality and viewpoint in some way? As in, suddenly getting a C on a test seems like no big deal because you're trying to make rent this month OR you feel like you can confide and trust someone who knows what it is to struggle, to be less than perfect... And to that point, does the size of the obstacle we overcome matter? Because the truth is that we are all individuals and we do experience situations differently (all of us don't react the same way to the same situation) and thus, might it take different size obstacles to yield the same results? Is there a basic threshold or minimum level of difficulty needed to get to the point where you are more laidback and accepting of others or just reap the benefit of hardship?

So what do you think?