Immersing yourself into a book can help to keep your brain healthy, help you gain knowledge, helps in focusing and helps with your concentration.
Reading books can also help relax your brain and fill your brain with little bits of information.
Immersing yourself in books is like watering your brain like you would a garden and keeps your brain sharp.
Studies have also shown that if you read a book often enough you can potentially keep your brain sharp enough to ward off dementia.