Unless i am challenged realy hard, we don't think too much about the thing. Even though I can not find the elusive soulmate, at least I can think hard why I need to find one / don't need to find one.
The "Eureka" thought is each is searching for the completeness (unity) one way or the other. As I wrote earlier, we can create that by acquiring something that is missing or completely annhilating the already existing entity. For us humans it is very hard to let go and relatively easy to acquire. Even nature has made the task of finding completeness acquisition oriented.
May be if we are able to find that elusive person/soulmate, may be we will find the path to reach that completeness/happinees.