Earlier quoted context omitted.
It is a complete shift in world view. In BC (before children) you lived one way, then in AD (after delivery) you live another. Complete and utter change in priorities, outlook, experience, meaning, fundamental shift that those without children cannot understand
And people with children cannot understand what it is to live a whole life in full freedom. I'm over 50 years old and I fully love my life as it is and have never regretted my choice of not having children (and never will). Not that my choice is suitable for everybody, but the most common choice is not suitable for everybody either.
And I mean proper life, backpacking for months around south east asia, himalaya, diving in remote tropical islands, doing extreme mountain sports to the fullest capacity. You know, stuff that adds easily many decades of life actually experienced.
It doesnt compare, it cant.
But there is a catch - to have a chance for actually being a good long term stable parent (and also having and raising kids in a similar way), 2 balanced individuals need to meet and be close to each other on many levels, and then keep working on it. Something I dont see often around me unfortunately in these me-me-me times, with corresponding consequences. Better having no kids than be a miserable parent, raising another miserable generation of permanent cripples.
Just wait till you hit 60s and the pool of nice things you can do keeps shrinking dramatically, I've heard such phrases before and then heard regrets some time later.