The room doesn't change. The acoustics don't change.YOU change from day to day. Dependent on how relaxed you are, or how much chi you have accumulated, or whatever, during the day is dependent on how much you will actually enjoy listening to SOUND.
I have the same problem. I will actually go for weeks without even listening to music except in the car, and suddenly start again and listen every evening for an hour or more.
Its all in our heads. Some of us need variety in our sensory inputs.
Marlboro