As a older than this person, I feel like it’s around the time most people have that first large step of retrospectiveness where they see their current self has deviated from their self they thought they were previously. They realize they have autonomy to craft themselves. They realize there are more important aspects to life than their grades/sports/hobby or whatever things they built their identity around for the first 20-25 years. Anyways once you realize it, it’s an interesting topic to write about as you’ve become a completely different person from the one you were maybe 5-10 years prior. Because you’re likely transitioning into adulthood (maturity wise). As this continues in your later thirties and forties, it’s just status quo adulting and not as interesting to write about.