It never stops changing, but there is a significant freeze around 25. From about 12-25 there are massive changes to the brain. It also coincides with them first gaining true freedom, and learning the pros and cons of that.

I dunno, I'm so stupid that I'm pretty sure my brain has stopped developing, and, in certain areas is regressing.

Maybe, but it's definitely true that the frontal lobes are typically significantly underdeveloped in the under-25s, resulting in impulsive behaviour with less caution and poorer long term decision making.

There's a time in your life when headlessly jumping out of the nest is absolutely the order of the day, and it's late teens and early twenties.

Having a safety net isn't a bad thing at this point, at all.