[hkmurakami]

It's just human relationships in general -- repeated serendipitous contact leads to relationships, platonic or otherwise.

I believe that adults' stated difficulty stems from a lack of such an environment with few exceptions like church or sports clubs.

[koolba]

That’s also the secret to finding someone who matches your cultural tastes or background.

You can’t pick who you fall in love with, but it’s easy to restrict the set of candidates.