A question for the masses

Is it inevitable that once the shine of a new job wears off, it's not going to be fun anymore? I ask because I have a job that, on paper, is perfect for me. But sometimes the day-to-day drudgery, the details, the annoyances make me long for something else. What that something is, I don't know. How can a person find THE career he or she is made for? Is there such a thing as the perfect job?