That's why I'm not being close friends to girl. If I want to be more than friends, like BFFs, the end goal of a potential marriage should be discussed at the beginning. And in being friends, I would keep the distance carefully, since anything too friendly may be a biological cue, even if it looks like just friendly.

Hanging out with a group? Fine. Having one on one conversation in the public? Fine. Physicals, friendly chat in private (including on internet), too intimate topics without a scientific reason, etc. These are all love triggers.

Someone with the mindset CE is describing could assume everything as "probably has another reason" and say "I may not be closer to being loved more than this, ever". So my principles are especially helpful in preventing such results. No BFF crush, no risk of losing that relationship.

For relatively confident people like me(of course, I'm not like a pick up artist level confident, but I just know that I have both good and bad points), these principles help in not wasting time and emotions on a relationship that won't work. For example, currently I'm very busy, so I don't try to find someone to get married. If I find an opportunity, not missing is still important. But and female friend currently would just be friends, unless they ask me for a relationship.