I think, as many PP have pointed out, it’s a combination of different factors and influences.
I met DH at 24 and am now 38. I was very, very broody for a bit at 26, but wouldn’t have dreamed of having children, we were conditioned to think that was too young (despite my mum having been married at 18 and had had her first child at 20). We got busy working, bought nice things, had nice holidays. I looked forward to the day we’d have kids though. In my head, I had images of me floating around on maternity with a little baby, in a high chair, feeding it nutritious home cooked meals whilst it gurgled happily at me.
I decided to become a teacher at 26, I love working with children, I think they’re great. Through teaching, I have learned a lot about child development and met countless families. DH and I both have older siblings, so we started having nieces and nephews around the same time. I’ve seen all of the possible outcomes of having children - from the good, to the bad.
DH and I decided not to have children when I was about 30. We liked the lifestyle that we had built. Children just looked like weekends full of birthday parties and sports clubs after a long week of work. It looked like sleepless nights and endless worries. It sounded like more work than reward. As a teacher, it looked very much like taking my work home with me. DH is big on the environment so that was a factor for him.
Now, I’ve had enough friends who have had traumatic births and PND to realise how big of a risk giving birth actually is. I don’t want to take a year or more off of all the sports that I do, at my age, it would be difficult to get back into them after time out and giving birth. I’ve realised that despite loving my classes of upper primary, I’m not really into being around under 5s.
I do think, if the expectation had been that I would have had children in my early twenties, I’d have just done it and probably enjoyed it for the most part. But there are so many different options and so much information out there, that people are making the best choice for them. We’re now both hoping to be able to retire early as a result.