Things I do so my brain does not rot:
Read something new.
Learn a skill I never tried before.
Teach and explain concepts.
Ask questions.
Try, fail, and try again.
Your brain needs exercise too, not just your body.
true, all you mentioned are right, with this your Brain keeps developing and also remains smart as it acquires new things everyday. As most intelligent people would say "the day you stop learning is the day you start dying" so learn new things everyday to keep your brain active.