Know what it is, and make up for it. If you are still at school, you can ask your classmates to help you borrow the books you want to read. If you graduate, you can buy your own books (online books are convenient and cheap) or borrow books from the local library.
In fact, studying after work is more important than studying at school. But many people often read less books after work than when they were at school. At school, a teacher once said that it would be nice if I could read two books a year after work. But as long as you want to read a book, you can make time for it.
Reading for half an hour before going to bed every night, you can still read a lot of books a year. That's what I did.