My last gf wanted to get married fast, but she knew i wouldn't propose before a year of dating, even though i knew i wanted to marry her. But she understood my reasons and was glad i was not rushing. Despite spending months of talk about how she wanted to get married, she dumped me. Now where would we be if i had rushed into marriage, then she had the same reasons later?
Fenner and notsure are the exceptions, not the rule. Most people who rush into marriage end up unhappily married or divorced. And this whole 'people just know' thing sounds good, but everyone 'knows', even though most of those that 'know' end up never getting married, getting dumped or divorced.