How do things go "too well?"

Ladies, what's going through your head when you break up with a guy because things are going too well? Or when a guy is too nice? Or when you're looking for commitment & love, and then back away when things get too serious? I've been in and seen friends go through both of these situations. My most recent relationship ended recently after everything was going seemingly perfect, when she couldn't stop telling me how happy and lucky she was. When she was so amazed at the things that I do, and how head over heels she was. Then at the drop of a dime, she had to end things, and wouldn't let me in even though she clearly still had strong feelings for me. I've always treated my partners like princesses, and have always been told, "You didn't do anything wrong. You were an amazing boyfriend" after the breakup. If I'm so amazing and things are going so perfect, then why did it have to end? I can only be told it wasn't my fault so many times before I start to think that I am the problem.
Is there more to it when things are going "too well" in a relationship?

To be honest, when a girl says "you're too nice" it's usually her nice way of saying you're clingy and need to back off a bit. Treating a girl like a princess is one thing, smothering them is another. Girl's like space and independence. We also like a bit of a challenge some times. Sounds like you might be a bit of a doormat. Man up.

If it seems too good to be true, then it probably is.

A few things here:

I wouldn't want to be treated as a Princess. I'm simply not a princessy type of person. Instead, I want to be treated as an equal. I don't need a guy to do loads of special things for me - I just want respect and someone to share a laugh and life with. Generally speaking, I reckon that only Divas want to be treated as a princess - and would you really want to date a diva?

Also, most women have learned by experience that men can't sustain treating women like a princess anyway. Yeah, sure it's all flowers and fancy dinners at first, but after 10 years and two kids she becomes resentful that he doesn't do that stuff anymore. She feels like she's been tricked into accepting a guy who isn't how he first seemed.

Start treating women like women - not like a princess.