Not to say that this is wrong... I have seen it.
But...
... I find it to be more true when people (guys and girls) have a "small town" mentality. I've seen it a lot. They are trapped in their own bubble, they lived, grew up, went to school, college and only ever met people directly from their own area and social circle. For some reason they just don't branch out. Meeting someone new or from somewhere else or even venturing into the outter world seems to not agree with them.
They'll have the mentality that their high-school sweetheart is "the one", and always want to return there.
It's not just a woman thing, or a beautiful woman thing, I see it an all types of guys and girls. They won't ever do what's scary and venture into the world and into the unknown.
On the other hand, I find people who've either traveled, moved for college, moved for work or dated outside their immediate social circle early to be much more open, much more interesting, more open to all things, and more willing to meet and date all sorts of people.
I don't really know if there is a way to combat it. As you said, they tend to gravitate back to that guy from the past. Even if they meet someone new and exciting, they don't see the longterm potential because what was there before was just "meant to be" even if deep down the reason they are on and off is that, it just isn't working really.
I met and dated a girl like this before the new year. She was nice, cute, wholesome, etc... but she wouldn't ever leave her hometown, never traveled out of state, or further than just into the city really, she even still lived at home at 26 and coming across town to see me seemed to be a big deal like we were in highschool or something!
But she held a strong flame for an ex. She seemed really torn, I think she felt at some point like she had found something new and exciting but there was such a strong push from both her ex and her family to not "go outside the circle" that it just didn't work... infact she got back with her ex after me and last I heard they had split again... wash, rinse, repeat.
Maybe this is just pulling from my own experience. I think it has more to do with someone's upbringing and life experiences.
I've also encountered it much more here in the US than I have in my home country. Some people seem to get so sucked into the world of their high-school or college bubble and just won't leave it.
It's a little different where I'm from since boys and girls grow up and are schooled seperately so when they reach 18 there is a more natural willingness to branch out and meet new people as your main social circle as a kid will primarily be of your own age and gender, there is no other choice.
