I'm not OP, so I can't read their mind, but I don't think they meant that the second baby happens on accident. Instead, what they're saying is that if you want to have kids and not have them spaced out too much, it ends up making a lot of sense for the woman to become a stay at home mom in situations where the family can afford it.

When giving birth at the hospital the nurses was all saying "See you in 1-3 years!". It's nothing uncommon indeed. After that ordeal our thought was more like "In your dreams!". No, it wasn't one of the fast, uncomplicated births, it was more like suddenly getting overrun by doctors and other white robes, whisked away into operation and then a very broken back for six months.

Not sure where you’re at now, but a common experience is that the memories of how difficult childbirth and newborns are start to recede and then you’re ready to have another go.

This.

The brain is exceptionally good at repressing bad memories. The effects of lack of sleep on memory / brain function might play a big part of it. (Just speculating from personal experience, I have no formal knowledge).

Yes, it took us about five years to get to that point.

I see, yea that could make sense in many situations.

Sure, but there is also the biological clock ticking of the female. Add to that if she wants multiple children, that adds up even further.