It’s possible to learn from your mistakes and then pass that knowledge on to your mistakes

Fixed it for you

It’s also possible to not make unreasonable demands that are likely to lead to a miserable life and/or prematurely marrying the wrong person out of pent up horniness.

This is an example of learning the wrong lesson from a mistake and consequently passing it down.

If the mistake is having a kid too early, the lesson should be “If you’re going to have sex, be properly prepared with someone you trust to actually be on the birth control they say they’re on”

Not “no sex until marriage”

It’s also possible to be a hypocrite.

And also, it’s possible to be a massive hypocrite, like their parents and their parents’ parents 'fore 'em.