soul + mate = what??

Why do we feel the need to be wanted and loved? Is loving ourselves so hard that we look to others to fill the void we cant fill ourselves. All anyone talks about these days are love and soul mates.. what is a soul mate? Some define it as the person you are destined to be with.. but how do we know? How are we supposed to tell who our soul mate is and why do we have to go through so many assholes to get there?... I just dont understand it...