Question from a Worried Girl

If you’re a guy and want or have kids; how old were you when you knew, did you always know?
If you’re woman and want or have kids; how old was the guy in your life when be decided he wanted kids?

To both, if you don’t want kids; why don’t you want kids?
(P.S. That’s not suppose to sound judge-y for not wanting kids, I’m just curious as to why.)

I’m curious, mainly because I’m having a slight moment of panic, again.
I’ll update this post once I get some replies in the comments, or eventually if none appear.

Thanks for your comment, I appreciate it. I need to help/comfort/understanding.