I realized yesterday that I accidentally developed the habit of thinking of downtime as a net positive, value-added activity.  I was thinking of the things I had to accomplish on my day off, and one of those things was to sit on the deck in my lounge chair and read a book, possibly accompanied by alcohol.  By accomplishing that, I would be accomplishing something, which is a positive thing, as opposed to thinking of it as sitting around and doing nothing, which is a negative thing.  Suffice it to say, mission accomplished.