How do people become close friends or SOs and then find out they had little in common?

I vote for this for the understatement of the history of humanity.

I think this is a key point, and clearly expressed.

One of the things I like about participating on a board like this is it forces me to think about questions I might not ask myself without a bit of prompting. There are lots of things couples might never get around to asking because they’ve never realized there was a question or never really thought about what their answer would even be.

A variation of this problem.

Pick an “issue” that people might feel strongly about one way or another. Say, on average 50 percent feel one way and 50 percent feel the other on any given issue.

Two issues and only 1 in 4 will agree with you on both. 5 issues and now only 1 in 32 will. 8 issues and its one in 256. 10 issues and its one in 1012. It doesnt take too many more to get to one in million.

There are MANY things in this world to feel strongly about, way damn more than 10 or so. Even if you really know and like somebody, there is almost certainly something that will eventually trigger a “Bill is such a nice and smart person, I just CANNOT believe he thinks such and such about XYZ…I thought I really knew Bill but apparently I don’t !!!”

Those specific examples you provided were very insightful. I was having trouble imagining what could be a real, significant issue that could fly under the radar for a long time, and those were all excellent examples that made me realize how much I still have to learn about my SO. Thank you.

I second this. In fact, way beyond our college years, my last serious girlfriend and I had a lot of intoxication in common. We fell in bleary love, rat-arsed. This gives both parties an easy way to ignore the other’s faults and incompatibilities, and anything you do argue over can be blamed on the drink. For years. We clashed in politics, class, taste, interests and even sex, only really ‘clicking’ in the pub.