Jeff, i 'upset' my oscar's schedule all the time and Gus doesn't care what happens to his tank or anything. i've moved fish out of there, he used to have an angel pick on him something fierce, changed substrate, removed substrate, done huge water changes where Gus was barely covered with water for a short time, had him in a 2 gallon pail for a good while when i moved apartments in fall of '09, moved the tank across the room, changed feeding schedules/food types/amounts, fasted him here and there for a day or so, and i also have a 6 year old that likes to hold things up to the tank to see if Gus 'likes' them or not, lol.
did i just luck out with an incredibly un-moody and adaptable oscar? hahaha!