This year I felt the need to call out of work for an entire week.
Why would you feel the need to call off for a whole week?
I wanted to finish an entire book.
It sounds like you had a good break. It is good to take a vacation and/or break from work every once in a while.
I should be able to call out of work whenever I don't feel like working.
Well I don't quite agree with that. I do think it's fine to take time off to focus on other things in moderation. But doing it all the time you don't feel like working isn't right.