It’s a risk to have a child at any age but the risk does raise as you get older scare tactics says it doubles and such after 40 but that doubling is like a 0.5% chance changing to a 1% chance. Adam ruins everything did a piece on this that explains it pretty well.
Maths unfortunately is hard to teach all at once, 1 year there’s no negative numbers next year there is. Then they make it harder by adding letters. Get high enough, and you start doing stuff with infinite numbers, which I was also told can’t be done.