Why a partner?

I often wonder what it is that most of the people in this world are looking for a partner. Are they not happy with themselves or with their family? What is this which draws two strangers towards one another? An attraction that overcomes the inertia of having to leave the comfort of one’s close ones their love care and spend the rest of their life with someone they have come to know so recently.
I have known a lot of instances where the guy and the girl had to marry against the will of their families. What is it that gave them the strength to overcome the obstacles set by their loved ones - the ones who cared for them loved them dearly? Love people will say gives them the strength and I don’t disagree with that. But what is so special about this love? What exists between them and their close ones is also love, isn’t it? So how can one love which is so young overcome the love that had grown over the years as they grew up?
Hard to find an answer to this and that is intriguing. I feel happy when I see couples happy with one another deeply madly in love with each other but this question seems to bug me most of the time.
I have thought on this long and hard and guess I have a possible explanation for all of this. Human are by nature very self-centered. They love themselves more than they love anyone else in this world. I know many of you disagree with me at this statement but it’s true we accept it or not. I guess that happiness in life is one of the most important goals of our life and each human being strives to get it.
We all know very well that the comfort and love of our parents our family will not be there for us for ever. We realize that this is extremely precious to us yet deep down we are all in search of an alternative. An alternative that will sustain us and keep us in the same state even when the “comfort zone” of today is gone. That is the single most driving factor of finding a partner.
Here I must say I am specifically leaving out an important equation out which is the physical need of humans. I guess that is an entirely separate subject and dealt with separately although I have known people who want to treat that in the same domain. Have u ever read Ayn Rand? U will understand the philosophy of objectivism and what I am just talking though it has been exploited to a far greater degree than I personally believe in.
So when people do find their partners, their gateway to happiness in life, they don’t want to let go of it even if it means their sacrifice of their current abode of happiness and love.It might sound very harsh and objective way of looking at relationships but I guess it has truth in it. So all you couples I don’t at all criticize u….u have done the right thing and presented with an option I would do the same.