I learned this last year during one of my foreign trips and give this feeling a name POWER OF TAKING REST
One of my meeting was re-scheduled and I had full day to spend doing nothing.
I took rest. I put my mobile aside went down the lobby had gup shups with strangers (other nationals), had a walk in nearest market, watched TV, bought & ate some fruits, and looked out of hotel window (from 16th floor) to enjoy the scenic view.
And next day for meeting I felt myself so fresh. Then I understood that its POWER OF TAKING REST
Hope you will have good time too.
BTW, there is definitely a difference of driving when hobc is mixed in regular or premium fuel. I will suggest you to give it a try too 