I wonder if the things we feel most passion for are the things which we first feel empathy toward. In my life, I've felt much deeper about the people or situations with which I've been able to empathize rather than sympathize (which makes sense, since by definition empathy is stemmed from an understanding of another's pain which sympathy cannot possibly match).
It might be that some friendships fail because people sympathize rather than empathize. No, you don't have to have the same life experiences. But it seems like those who empathize with people are much more productive toward healing or help than those who sympathize.
I did a little googling on the topic of empathy and sympathy and as I read through some of the comments on this article I stumbled upon this:
"Someone has dug a large hole and fallen into it, now unable to get out. The empathizer will understand and retain a healthy ability to help them out of that hole. The sympathizer will run and jump into the hole to console him."
A humorous example, but very true. Although I sometimes feel selfish for focusing on organizations which cater toward my past hurts, I may make more of an impact for others by supporting groups which I relate to best.