There is this really cool, Zen-like story that explains the benefit of reading with a beautiful analogy. I can't remember where I found it—it was probably a comment somewhere on Reddit. Regardless, here's the version of the story I remember.
Once, there was a kid whose grandfather always had his head buried in the books.
Curious about why he read so much and how will he ever remember everything he reads, one day the kid asks the old man:
"What's the point the reading all these books when you can't remember everything?"
The elderly man smiles and tells the kid that he will answer his question if he agrees to do an exercise with him. The kid agrees to take up the challenge.
The sexagenarian asks his grandson to follow him in the backyard where he had a garden shed and an empty water trough a few feet away. The old man walks behind the shed, gets the water tap running, and points the little boy to a rusty bucket lying next to the tap.
"Use the bucket to fill that trough with water," the old man says.
The bucket wasn't just rusty but had big holes in it. The kid finds it absurd but agrees to play along. He makes several trips from the tap to the trough, ferrying water in the leaky bucket that lost more water than it could hold.
By the twelfth time of repeating the process, the little boy becomes visibly frustrated. He tosses the bucket on the ground, puts his hands on the knees, and asks his grandfather what's the point of using a bucket leaking from all over the place to fill a trough.
The old man smiles again and gives him the answer.
"It's true—your rusted bucket wasn't able to hold all the water it carried. But look at the bucket again, son. It got rid of a lot of rust in the process and now it's cleaner than when you picked it up first."
Our mind is like that leaky bucket when we read books. We certainly can't remember everything that we read—but the habit of reading cleans up our rusty minds and fills it with fresh knowledge every time we fill it with a new book.
Read books even if you can't remember most of them, because the process is as valuable as the outcome.