I think maybe it's not even about a specific relationship, it's just about the girl herself. She's the sort of girl who throws herself into her relationships with all her heart, but nobody she finds is willing to do that back. They even get amused by her intensity, and possibly scared off. She needs to know that there's somebody out there who believes in love as strongly as she does, or she will end up a cynic all alone because she isn't willing to settle for a cheap imitation of what her heart wants to find.
I think maybe it's not even about a specific relationship, it's just about the girl herself. She's the sort of girl who throws herself into her relationships with all her heart, but nobody she finds is willing to do that back. They even get amused by her intensity, and possibly scared off. She needs to know that there's somebody out there who believes in love as strongly as she does, or she will end up a cynic all alone because she isn't willing to settle for a cheap imitation of what her heart wants to find.