I watched your argument Neeraj/Ebisu-san and indianbaba and if you allow me, I would like to ask a few questions myself on the matter.
Neeraj says that if you are in love with someone but can't marry him for some reasons, you should be happy. I would like to know what kind of reasons could there be.
Your mate being already married? Your parents not wanting your mate/ vice versa? Social factors? Age factors? Wealth factors? Someone blackmailing you?
Each case is different. If your mate is already married, then the relationship is wrong - and should not have started. If it's a parent thing, you shouldn't bother listening to them. You're their child, if they can't accept your decisions, let them not. But don't be bothered. If it's a factor thing, you can always overcome it. Blackmail? Well, that's kind of complicated. But if you really want to be with someone and get married, you can find a way.
Let's say that when you love someone really much, you want to spend the rest of your days with them, and thus get married with them. It is only natural. It is not about insecurance, it is about deep connection and bonding. I am not saying that if you are not married with your mate you are not bonded, it is just that marriage brings you even closer.

Indianbaba I agree that it is our heritage to live and get married with a very special someone, but I also think that we are able of loving more than once in our life. I am not saying that we can go around and love just about everyone, but in someone's life there may be two or even three "great loves". If they are many, they are not real. I am talking about only a selected few, and if someone is lucky, just one, person that changes your whole life.
The person that becomes your "light" and guide, the person without whom you feel lost, empty and dead. That is the one you should get married with, and that alone. And I think when the time comes, nothing can keep you two apart. If you want to join your lives, you'll find a way.
Just my thoughts.