I have read a lot of books, but then most of them were forgotten by me, what's the point of reading

I ate a lot of food when I was a kid, most of it is gone and forgotten, but some of them, for sure, have grown into my bones and flesh. The same is true for the changes that reading makes to your mind: it slips into your veins.

Reading is a subtle thing. Reading is not doing arithmetic or answering questions, and it will not immediately present a visible result. But its impact on a person's life, like making many friends, appears strangely at critical moments.