Books started off as a way to document information, but eventually they developed genres like fiction, romance, and horror, thus transforming them into a form of entertainment. Many people see books as an escape from the real world. Some genres are better for getting out of the world than others. For example, Fiction would help to escape far more than an autobiography would. Some books that I, personally, enjoy are Sci-Fi, or fiction.
Fiction means stories that are not true, sometimes including unreal elements. An example of a fictional book is Twilight or Divergent. Neither of these books actually happened, which is why they are considered fiction. Some fiction does not include unbelievable traits, but since it did not actually happen it is still considered fiction, but it is actually called Realistic Fiction.
In some way, everyone is an author, but to their own story. As your life goes on, you are writing that story down in your memory. Make sure that your story is one that you are happy with. Books, though are typically associated with nerds, or geeks, are not actually dependent on who you are. Books are for everyone, so if you want to read, do it and no one should be able to shame you for doing so.