It's pretty hard for me to fathom now that the age for so many "rites" of adulthood keep increasing in much of the developed world, but once upon a time even a 15 yo was considered a proper adult in most societies. I don't miss the days of child labor, but I do resent how we postpone basic expectations for independence and maturity and granting people responsibilities commensurate with their actual capability ever later and later (if at all), as if our lifespans were increasing exponentially (which they most certainly are not). In another era, an older teen dealing at a casino would seem completely reasonable to me tbh.
That's because science has advanced. We used to think: "Oh, you're sexually mature? Great! You're an adult."
Now we know that the brain continues developing well into your 20s, and actually varies based on the person, with it being ~25-30 before it's
mostly developed (obviously it continues minor adjustments and stuff). This is why, when you often don't feel much different at 18 vs 22, but feel much different at 30 vs 26. I'm 32 now, and up until I was ~28, I felt like I was still the same person I was when I graduated high school at 18. Now I look back at even my 24 y/o self and facepalm at how immature I was, and I was working a corporate job at 24.
Edit: and it's obviously not a "you wake up one day and suddenly your brain is done developing." It's a gradual procese. But if we use 25 as the starting point for "basically done developing" that's still 4 years past the "you can drink alcohol and smoke tobacco" age and 7 years past the "you can die for your country" age here in the USA
