I think the word "attraction" is the key. Being attracted to someone means they catch our eye. The other ones don't. So they're invisible.
We all think that everybody sees us and has an opinion. It's totally natural. Our minds are confined to our own bodies, and we create the entire universe inside our heads revolving around our own bodies. But so does everybody else. We are the most important person to ourselves. But only to us, no matter how much we'd wish they would care about us as much as we do.
Isn't that pretty much what growing up is about? Young kids are always upset about other people not understanding their specific problems, while they at the same time deny that other people might have different priorities that are relevant. Having a pimple on the nose for a young kid really can destroy their world.
Anyway. I think the trick isn't to be perfect to everyone, but to find a person to whom you're perfect to. Sure, having "ideal weight" might make that easier... but you don't want somebody to fall in love with your image, but to fall in love with you. And to those who thinks I'm saying, it's really the inside that counts... well I'm really not. I think the outside is just as important.