It is much easier to fall in love with people you have spent a lot of time with. Same thing with friendship, and I guess rivalry too. The keyword is "propinquit

It is much easier to fall in love with people you have spent a lot of time with. Same thing with friendship, and I guess rivalry too. The keyword is "propinquity". In a small village, it is natural, less so in a busy city where you meet with a lot of people, but don't really spend time with them.