> When people say "the brain is still developing until you're 25" it means "your brain is noticeably worse at learning after the age of 25".
No, it means that your prefrontal cortex—which is involved in a wide range of higher-order cognitive functions (planning, decision making, working memory, personality expression, moderating social behavior, risk processing)—is still developing, so until it does fully develop (colloquially at age 25, but it can vary per individual), you may lack those skills because you physically lack the plumbing for them to be present:
> They also found important clues to brain function. For instance, a 2016 study found that when faced with negative emotion, 18- to 21-year-olds had brain activity in the prefrontal cortices that looked more like that of younger teenagers than that of people over 21. Alexandra Cohen, the lead author of that study and now a neuroscientist at Emory University, said the scientific consensus is that brain development continues into people’s 20s.
No, it means that your prefrontal cortex—which is involved in a wide range of higher-order cognitive functions (planning, decision making, working memory, personality expression, moderating social behavior, risk processing)—is still developing, so until it does fully develop (colloquially at age 25, but it can vary per individual), you may lack those skills because you physically lack the plumbing for them to be present:
* https://en.wikipedia.org/wiki/Prefrontal_cortex
* https://www.urmc.rochester.edu/encyclopedia/content.aspx?Con...
> They also found important clues to brain function. For instance, a 2016 study found that when faced with negative emotion, 18- to 21-year-olds had brain activity in the prefrontal cortices that looked more like that of younger teenagers than that of people over 21. Alexandra Cohen, the lead author of that study and now a neuroscientist at Emory University, said the scientific consensus is that brain development continues into people’s 20s.
* https://slate.com/technology/2022/11/brain-development-25-ye...
Of course even post-"25" some folks still may lack them as well, but at that point there's no longer anything physically preventing you from doing so.