Hubby and I got married young. I was just 18 and he was 20. We decided not to have any children and just spent time traveling and working.
When my grandma died when I was 34, I realized (late, I know) that one day I would be the "old lady" with no husband (statistically), and no children. My grandma relied heavily on my mom to watch out for her best interest, and I had an epiphany that to be childless could be a bad idea. I know this sounds entirely selfish, but it's the truth of why my husband and I began to try to conceive at 35 and 37 years respectively.
Our son was born five months past my 40th birthday. I didn't want to risk having another that may have health problems, so we went the surgical route for contraception.
I'm 45 and DH is 47 today. We have a son that I wouldn't trade for anything and many days I'm sorry I was so selfish and didn't have more.
Thanks everyone for weighing in on this topic. It struck me as being one similar to the whole "nature/nuture" thing.
