Putin - Firstly, unless you have a kid of your own, no one could ever explain that feeling. So, your question is sorta moot. Unfortunately, you'll never really get it...no big deal, you just won't.
Why do they talk about them so much? Because having a child is life-changing. You can go through life and love other people...your mom, your dad, your brother, your sister, friends, your wife...etc. But creating your own child? that is something else entirely. Love for a child is all consuming and very much unconditional. It's indescribable.
I don't know this, but I can only imagine that losing a child has got to be the worst pain in the world. I would not wish this on anyone. I'd rather die a thousand deaths than lose mine.
I hope this makes it clearer, though I wouldn't expect you to understand.