There are people that are going to love you and people that won´t be affected by you and your existence. There are people that are going to notice you and people that won't even look at you at all. And that is completely fine. It´s not their loss, and not yours either, call it chemistry if you like, or attraction, or "they don´t have what it takes" or even "I don´t have what it takes", it doesn't matter if we don't have a decisive name for it or a certain definition, it is what it is. 

But when you do find someone or get found by someone that sees you, notices you entirely, pays attention to your body, mind and soul and you feel the same way back towards that person, now tell me if that physical and chemical and psychological connection doesn't feel like something marvelous, so beautiful that we almost tend to call it "magical". 

But it´s not magical, it´s just compatible. 

Don´t feel sad over an incompatibility.