When I was still dating Arya, I remember talking to him about why I think certain relationships work and some don't. I have had my string of trials and errors, and although some of them are good people I couldn't bring myself to the 'I do' stage of a relationship.
I had a theory (or more accurately, a proposition). That inter personal compatibility could be explained by the pyramid below (click to enlarge):
The lowest level, the primary, is the most basic indicator to compatibility. It is the values with which we view life. Two people need to share compatible values in order for the relationship to succeed. Within this level is usually the moral and ethical debate over right and wrong, what kind of person we strive to be, etc.
On the secondary level, you have social fragmentation. Socio-economic class, profession, and nationality are examples. Although they are ideological, they are less fixed than life values and they are adaptive to circumstances. The logic is: an Indonesian could adjust to life abroad but their moral indicators (primary) would stay the same.
On the tertiary level you have hobbies. Music you listen to, sports, things you do in your leisure time. Usually our hobbies determine which sub culture we are part of. Movie buffs, geeks, TV addicts all emerged from the choice of past times but they shape sub cultures.
Having said that, I argue that a relationship could only work if the couple is compatible in the primary level. Afterwards we work our way up the pyramid. A relationship can survive with just primary compatibility, but it would grow more intense if they're compatible on the secondary and tertiary level.
This is why 'pernikahan taaruf' works. You wonder how is it possible that two people that have never met before could build an intimate relationship. It's because that is the basic values they believe in. They adjust the secondary and tertiary level according to their primary 'needs'.
And that's also why the relationship of two people with the same profession and hobbies, which is so easily read externally as 'the most compatible couple since they can talk about work' could fail - because my argument is that they might not share their relationship on the primary, most important level.
To be honest I made this model up based on my own personal experience and it's probably faulty in more than one context. But it's nice to conceptually explain why my relationship with Arya works. Cheers!