is it true that the brain is fully at 25-30

[OnlyNatural]

Yes, the prefrontal cortex (decision-making, impulse-control, higher-level reasoning, etc.) doesn't fully mature until about age 25.

Being a teenager can be confusing and frustrating... but it gets better.

Better? Really? All I noticed was a more severe kind of problem. However,I've been far less confused since I realised humans are a virus from which the planet will recover sooner rather than later

Well, I guess I meant the angst and emotional turmoil and identity confusion so often characteristic of adolescence. I know personally I'm extremely happy to be out of my teens... that was a rough period. When you grow up, you understand things a lot better, but you're right, that comes with it's own challenges.

I also hope the planet recovers from our widespread destruction one day. The human species won't last forever, I just wish we'd do a better job of maximizing the time on Earth that we have, by using our supposedly intelligent brains.