1) In response to the "know yourself" bullet: I met my now wife at 15 - we learned a lot about ourselves between then and when we married at age 22. But we were pretty much committed to marrying by age 18, even though we learned a lot after. You can learn with another person.
2) Life pro tip on understanding other people (this is a quick reinforcement of a bunch of points in the article): if someone is behaving irrationally, 99% of the time its because they are subconciously insecure about something.
3) The odds of first marriage are better than 50/50. That statistic is for total marriages, but people who divorce once on average divorce multiple times. Success rate of first marriage is something like 65%. Also, that success rate goes higher if you're high income, like most of HN.