Ezekiel 25:17
Veteran
Humans beings #1 purpose in life is to procreate & keep the human race alive.
If you dont have kids, you will always feel unfulfilled. That's why people who dont want kids end up getting a pet. Everyone has something in them to want to nature & raise.
Except kids is just one small fulfillment, and that's IF the kids goes on to be a good adult. If your child grows up to be a criminal, then what?

If you want TRUE fulfillment you have to strive to be above average in all aspects in life. Kids is one aspect, but you should be touching other goals like career, helping people, and hobbies.