> Meanwhile at trail running meets, I bump into 60 year olds still giving some 35 year olds a run for their money.

Yup, this is very much key.

I am perfectly capable of keeping up with my kids.

My 72 year old father who is also in good condition keeps up with my 3 year old son.

The difference I see between a reasonably fit 40 year old and not is the massive gap.

So if you hear anyone telling you they can't imagine late fatherhood ignore them, they obviously aren't good at imagining things.

The chance you will need to take care of both your kids and your parents in your 50s is pretty high (not even going into you and your partner), while facing declining health yourself.

Could be easily manageable, or not. Ask me in a decade.

But one thing is darn true - if a good long term stable match is not there, no point pushing for kids. World really doesnt need more damaged folks struggling their whole lives to overcome shitty childhood. And thats fine, parenthood is not for everybody and there can be an amazing life to be had instead (and I mean it in best way possible, but that life shouod not be spent behind the desk and on the couch)

I know two men 18 years apart in age who became fathers at the same time - two months apart to be exact. Even though the older is an avid gym-goer, it's only the younger who can pull off popping back into full strength after less than 6h of sleep.

Interrupt that 60 year old's sleep twice a night with a newborn crying, add a bunch of new responsibilities, and I'll be impressed if he even makes it to the meet.

You're comparing people who have made exercise their #1 priority in life to people who have made their kids and supporting their families financially their top 2 priorities. It's a bullshit comparison.

My father is 63, raised three children and has had a successful long marriage and retired from a good career. He also goes works out daily and did for most of my childhood. He didn't make exercise his number one priority.