Creature of Habit

Today I decided to skip my yoga class because the deadline to submit a conference paper is tomorrow and it still needs a good amount of work. As fate would have it, I didn't manage to do any work after that and returned from uni in a funk. And I felt lousy for having missed my yoga class. Its not like I leave every yoga class feeling elated, although that has happened on occasion. I think what it is is I am a creature of habit as well as a fitness junkie, so any unanticipated change in my exercise routine which results in me missing an intensive workout makes me feel like crap. If it had been an anticipated change I would have swapped things around to make sure that I got in an intensive workout on another day. As it happens, I still did a reasonably intensive workout but that did little to lift my mood.
In what other ways am I a creature of habit? I have two fried eggs and two toasts for breakfast everyday. I cook chicken every weekend, and during the week I alternate between rajma and cauli flower and chole and brinjal. Who says you cannot routinize variety? Spontaneity requires time and effort, and I can't be bothered. My food schedule is varied enough without being a pain in the butt. Why am i this way? I would like to believe that a PhD is so consuming that you crave ease and simplicity in the other areas of your life, especially the day-to-day survival stuff. But, maybe I am just a stick in the mud.