I’ve got a 9 mo old, and planning to have a couple more. It’s a hard to explain feeling of fulfillment and completeness, except one where I didn’t realize something was missing until I actually had them. That said I look back to the time when it was just me and my wife and really enjoy those memories too, but those have their place, time and duration and when you have kids you realize that they are something with their own relish that you can enjoy too.
I’m also somewhat superstitious/quasi hippy so I believe kids bring their own karma and destiny into the worlds, which, when interacting with your own life can change it for the better or worse. Not necessarily a reason to have them per se but an observation nonetheless.
Overall it’s been an amazing experience. I love coming home to see my little guy, and make him smile which makes me smile in turn. They are amazing little AI machines. And you can’t help thinking And helping them become whatever they are meant to become in their fullest actualization.