Cher Lloyd - Want U Back

this song's kinda fun, but what's-so-me was just the title.
I mean, the beat doesn't sound like a sad one, but the lyrics shows how she's dying to want him back.
well, yeah, I WANT U BACK, I WANT U BACK, WANT-WANT YOU- WANT YOU BACK! URGH!

source

well, some part of this song is a bit selfish, but maybe we just love someone too much and we're sure that we can make them happy, so we want to be with them so badly and can't let anyone else to have them.