Although books can be crazy and strange and exciting and draining and upsetting and more all at the same time, the world of books will wait for you.
Also, when a book ends, it's horrible. If it's a book you've enjoyed that is. But there is always the opportunity to go back and re-read it, to turn the pages for a second time or a fifth or tenth time, to read the words again and to read them in the same way or differently. Again, that's something that you cannot do in real life- you can't go back and do things over or again which is probably another of many reasons why people will always find a sense of release in books.
Personally, I will always see reading as something I enjoy naturally, but when I take time to think about it, I understand the mechanics behind it. To open a book is to open a door to another world where the person you are or want to be doesn't change anything. The book won't be different if you think your head is too big or your eyes too small. The characters won't care (or know) if you aren't the best at everything, which is so amazingly great. Almost as amazing as the fact that it matters sometimes to us in the real world.