“Abducted by aliens and told the secrets of the universe by Jesus H. God” definitely comes closest. Because a kid is like a little alien, and totally abducts your life. (You think it’s your life anymore? Ha!) But who knew, pre-kid, that it was possible to feel these feelings? I’ve never in my life loved anyone with the depth and intensity that I love the Firebug. It really does feel like being told the secrets of the universe by Jesus H. God.
For the first couple of years, I figured there’d be a time when the feelings would kinda mellow out, and I’d almost get to a point where I started taking the whole dad thing for granted. But instead, it just keeps on getting stronger and deeper. My eyes will tear up at random moments, just thinking about him. It’s crazy - it’s like I opened the door to an alternate reality that looks just like the one I’d lived in, but feels completely different.
It’s a wonder to me that kids aren’t a controlled substance. They certainly don’t qualify for anybody’s ‘generally recognized as safe’ designation. 
That, too - I occasionally think about the fact that it’s not improbable that my son could live to see the beginning of the 22nd century - he’d be 93 at the beginning of A.D. 2101.