Yes I actually do think that some people are just better relationship people than others.
I have virtually been in a relationship since I was 17. I did have a long marriage but I have moved from one relationship to another, with very little time in between and I would consider all my relationships pretty successful (although marriage not-so-great in latter years).
I think the best relationship people like people. We are good communicators, affectionate, value our relationship and can compromise. How do you do in those areas?
Maybe there's something a bit genetic in it as well. My mother, sister and daughters are all the same.