Results may varies and everyone has a story
It used to be mid 20's is when people getting married and start popping babies thereafter so these people are timing themselves to hit a goal at a certain age. Some even focus on the big 30 for women as they are racing to pop babies as science has said that complication of birth is anything beyond the 30+ mark.
Then we get gen z, the group that is built differently. Gen Y, they rather not get marry or popping kids and they even have a financial acronym like DINK, duel income no kids or the Fire movement - Financial independent retire early and to get there, no kids are a given because children is a money constraint that goes against their narrative.
As for myself, I'm just a victim of circumstances. I don't plan anything when it comes to relationship. To get marry is easy but what to do after you get marry? If you can't figure this out then it is best not to get marry.
