Men have fewer easy opportunities to upgrade partners than women. That's why we can appear to have the moral high ground.
Yes, after a while I was all righteous "She dumped me, I'm a better person than her, etc", but when the emotional turmoil subsided, I found that I couldn't care less about who was more moral. If her istincts told her so, then all the better for her, I just want another partner for good.
Can you imagine how you would behave, if you had the constant opportunity that some good looking women do?
While it's obvious that with the same set of istincts I would behave in the same way, I don't know how I would become if I had so much success with women. My brain cannot really compute the long term ramification, it's stuck on imagining all the sex I would get...
Think about how some men change, when they learn about PUA or become high status.
Well, I'm not sure if the implication could not be reversed, but I guess that whenever you have more success, you naturally become more picky, and that if you're not able to discern right away the good from the bad, or you find someone who's really good at faking, you become a much more frequent dumper.
Information that surprises you is interesting as it exposes where you have been miscalibrated, and allows you to correct for that.
I suspect the users of LessWrong have fairly similar beliefs, so it is probable that information that has surprised you would surprise others here, so it would be useful for them if you shared them.
Example: In a discussion with a friend recently I realised I had massively miscalibrated on the percentage of the UK population who shared my beliefs on certain subjects, in general the population was far more conservative than I had expected.
In retrospect I was assuming my own personal experience was more representative than it was, even when attempting to correct for that.