The problem with finding work you are pasionate about is that it begins to take over your life. When asked to describe yourself, your job comes first. I think of myself as a Scientist before most other things.
Yet there is still the tedium, and I’m sure this is true for any job. Scientists with the endless repetitions, failiures, grant applications and standard-protocols, teachers with marking, planning admin, artists with ensuring there will be an income, be it taking arts-council funding or whatever. But these aren’t the moments to work for, and although these might be the reasons that you find yourself working when you’d rather be asleep, the reason you tolerate those moments is because you know whats comming. (Or rather because you may not know whats comming, and thats where the excitement lies.)