-in a very practical sense, i get to decide my own working hours. when i was working 8-5 before starting the PhD i had serious sleeping problems. when you can't sleep and then still have to get up to go to work, the day is sooo wasted. now, except when i teach, i know when i go to bed that if worst comes to worst and i can't sleep, i CAN sleep late to catch up and the day won't be wasted. thanks to knowing this i usually have no problems falling asleep as the anxiety of "having to go to sleep NOW" is not there (except when i teach...) so for me, this seriously adds to my quality of life!