Taking a vacation gets you away, and after awhile you begin to miss it and chomp at the bit to get back to it. You simply appreciate it more. Vacationing helps you reset your mind. Even though the mind is a mystery, we do know that it can get tired. Getting away on a regular basis helps reset the mind to its peak condition.
Every brain needs a good rest.
Vacationing makes your body stronger, with more energy for the battle by giving it a rest. Every week they take one day off. And then they take whole seasons off and allow their bodies to rest. Our bodies are the same. We need to let them relax, sleep more, etc.