I'm not very fond of children in general. Specifically, I am not fond of thinking about what my wife and I would have had to give up these past 11 years if we had children instead of finding a doctor willing to sterilize my wife when we were in our early 20's.
We enjoy being able to do what we want to do, when we want to do it. Our friends with children do not have this luxury. It's not so much that I "hate" children - I don't - but I prefer my life the way it is. People told us we were going to change our minds when those "biological urges" hit but we honestly never did. If you ask my wife or myself now what the best decision we could have made in our relationship is, it was the decision to not have children.
A few interesting links about the happiness (or lack thereof) that children bring to your life:
http://www.newsweek.com/2008/06/28/having-kids-makes-you-happy.html (Notice the title is tongue-in-cheek because the study found that having children subtracts from happiness in married couples)
Or this quote:
"As Daniel Gilbert, a professor of psychology at Harvard University wrote in Time magazine, "Studies reveal that most married couples start out happy and then become progressively less satisfied over the course of their lives, becoming especially disconsolate when their children are in diapers and in adolescence, and returning to their initial levels of happiness only after their children have had the decency to grow up and go away."
See the whole article here:
http://www.deseretnews.com/article/700119798/Studies-say-children-subtract-from-happiness-so-what-do-we-really-feel.html
So perhaps the secret to our long and happy marriage - I was 21 and she was 19 when we tied the knot; and we're still together and in love - was that we never had kids.
Food for thought.