Reading reduces stress and relaxes you
Distraction is a great way to get out of your own head and break a negative thought-cycle.
If you're stressed about a situation at work, or you're worrying about an upcoming date, few things will distract you — and therefore de-stress you — as effectively as a really good book.
Irrespective of what you've chosen to read, a well-written book can transport you to a completely different place, allowing you a little peace from the stresses of daily life.