I absolutely love what I do!  I tell my friends that it's literally my job to laugh and have fun every day.  I don't think there has been a single day of work where I have failed to do so.  And the days where it does feel like I'm more stressed or having less fun, it's usually a symptom that there's something I can improve.  So, while it's a LOT of work, it's the best environment I could ever dream of - I've been teaching for over a decade now and wouldn't trade it for anything.