There is a sad story about the brain's cells.
The cells are connected to each other by the strings namely, Axon. When a cell being activated, it makes other cells that is in the network of the related information of that cell to be activated. And that is why we can remind information and find, create and understand new things. but the sad story is that if a cell not being activated for a long time, the axons will remove their connection to that cell and it will be isolated so there is no more connection to reach that cell and slowly it will demolish.
So, why you people don't engage your brain.
Why you dont think of the daily current affairs.
Dont be indifferent about the incidents happen around.
Stop thinking about worthless stuff.
Stop doing routine jobs.
Try to involve your cells as far as you can in your life and you will see what happens next.
Your brain will grow.
Do you know how the Alzheimer's disease comes to existence?