>>12667067The myelinisation of the frontal cortex is a slow process, that finishes around age 25. At that point you dont become dumber, but your thinking does change a little. As far as i know there isnt much data on what exactly changes, there are some studys that suggest long term planning increases and also that language learning becomes harder.
If you have brain fog or mental degeneration or chronic fatigue, that might be a symptom of something other than aging, so go see a doctor.
