I'm not sure if going to the bathroom is a "smart" adjustment between conscious and subconscious, or if it's closer to firing neurons in the region associated with it (that is to say, instead of a communication networks, it may be closer to just flipping on a switch). What would agree with the latter, is that studies show that the region of the brain associated with it is overly active when under the influence of alcohol. I think resting all day (and as a result, not wishing to do serious work) could probably be better explained by less blood flow to the brain (and as a result, less oxygen) due to lack of movement. On top of this, our bodies tend to operate in 12-hour cycles. If you are active for a while, your telling your brain it's in that 12-hour cycle. If your inactive, your telling it your in your inactive cycle.