If you have hit 40 and you have never fathered a child, I say give it up dude. That criteria applies to me, by the ways.
I did come close to fathering a child when I was 24. At the time I had a girlfriend who was 18 and taking birth control pills. She told me that she had been told to take them for a month before having unprotected sex, but we kinda jumped the gun. I remember her calling and telling me that she hadn't had her period and I was sweating some fucking bullets, because at that stage of my life I was totally unprepared to be a father never mind married to that girl. Anyway, it was a false alarm as her period came late that month. After that I pretty much got scared about having unprotected intercourse with her, as much as I liked it.
I am at a point in my life now where I accept and enjoy being single and have no desire to be married or to have any children. I don't have the patience to be a parent, and there are simply too many issues and obligations especially in regards to properly educating a child. Looking back I feel as though I was pretty lucky in terms of the educational opportunities I had, and frankly I would never be able to raise a child without giving him/her the same or better opportunties than I had. And that is simply too much pressure to handle. I don't need it. And with the money I have saved by not sending a kid to college, I will soon be buying myself a new car. And if my schedule permits, an overseas vacation.