Sacrilege
Love between a couple comes from true giving of the self which really requires a marriage environment.
Dating can get you to the point of liking, attraction and feeling this is the right person and knowing that you have the right things in common and want the same things out of life. This usually comes for most people in 6-8 dates give or take.
Whatever else you want to know about the person can be learned post engagement. Some people force themselves to continue to go out just because they like the person and they may have nothing else on the table. But that’s not being honest with yourself and it only hurts you. As you know yourself from the story you quoted, you dated s/o for a large amount of time but then the right girl came along for him and it went chickchok. If its the right person you wil usually feel it a few dates in. My sister told me she knew by date 3 but they got engaged 6 or 7.
Oh and for the record, just because you love someone doesn’t mean you should marry them. Marriage is not just about love. Its about both moving in the same direction together.
I know people who dated (not the kosher way) and they loved each other but they knew it wasn’t the right move to marry each other. Dating requires intense honsesty. Its easy to fool oneself.