Let's look at the non Jewish world, where people date for years, and not only date, but "test drive" for years sometimes, before getting married, which lasts only a year or so.
This it's a more and more common trend.
It proves that before one is officially bound together (= harder to break up) people often do their best to be nice, considerate, etc, but once it's confirmed, they stop, with the expected results.
Bottom line: dating 3x ? Not enough. Dating intensively a few weeks vs a year? No real difference.