I am very, very, very much a creature of habit. I am also an inadvertent workaholic, which I think feeds into my habit-forming lifestyle. I get up at 9, go to work, work til 7 at the office, sometimes go for a run, go home, surf the internet, do more work, go to bed around 2. Weekends are more web surfing and working from home. My coworkers often make comments about the number of hours I work (70-80 hours a week), but honestly, if I couldn't work, I would be bored and unsettled. It's part of my routine, and I actually wish weekends didn't exist so I could work at the office those days as well. (I doubt i would feel this way if I disliked the work I did, but if I didn't work, my life would be just as routinized, and I'd just spend more time reading.)
I'm not bothered at all if my routine is disturbed during the day (e.g., I have to go do X when normally I'd do Y). I do hate not being in control of my schedule, though, so I generally hate traveling with my family, although I always go anyway. Within just a few days, I'm worn and just want to be back to my normal routine. I could be in the most amazing exotic place in the world, but guarantee I'd be counting down the days until I got to go home. (If I lived in amazing exotic place full-time or could stay there temporarily and just resume my normal routine, that would be totally fine.) My family's vacations are probably the most stressful time of year for me.