How many books do we read? Quantity is probably important but not everything. Quality is often fundamental, and choosing your book to suit your tastes and attitudes is the best way to create a small library of culture.
We often read without understanding because they are full of thoughts in our heads or because we don’t read often. It also depends on the genre of books: the most difficult are the intricate stories full of characters (mystery and novels) but also treatises on Philosophy.
If your intent is to have fun and not be too focused on the logic of the book, take a leisure book, I am convinced that the quality of the reading is usually more important than the content.
The length of the book is relative. If the book is very exciting we would like the book to never end. Instead some people prefer to read more books but short ones.
A book that has captured us represents a piece of our soul to be kept both in the library of books and in the library of one’s mind.