My parents were almost 40 when I was born. I was the little brother that wrecked mom's figure.
I wore. My parents. Out. At one point, my dad gave me a credit card and said, "you go ahead son. Me and your mom will be right here."
I decided when I was about 18 that I would have my kids when I was young enough to wear THEM out. And I did. No regrets. I was 33 when my youngest was born. I've fished and hunted, and hiked and skied and camped and traveled and stayed up all night with my kids.
That said, my dad was old at 50. Like, really old. I didn't feel old at all at 50. I have no health issues and still have decent energy. It's different now. I'm glad I did it my way. As I am really enjoying my grandkids.
But I also think 50 is the new 40. People are younger than the earlier generation at the same age. To each his own.