For me, my first born taught me that love is infinite, no matter how much I loved my wife, that little creature was getting all my love as well, somehow as if there were some parallel source of infinite love for the two of them.
Our second born, taught me that exact same lesson, again - that no matter what, there will always be three human beings in my life for which my love is infinite, and that I would step in front of a bullet for any one of them.
Whereas before it all went down, I was pretty much all alone, now I know for sure there are 3 other human beings I will want to say goodbye to, properly, some day.