I'm in the middle of a three-month term of medical nights. Seven 12-hour night shifts in a row, followed by a week off. Rinse, re-adjust body clock and repeat. It's not so bad.
But today is my birthday. At midnight I had a celebratory cupcake (thanks to my little sister) and the nurses all said happy birthday. And after I've slept the day away today, I'll come back for another 12 hour shift and it will still be my birthday. The prospect of working twice on my birthday does not excite me.
There had better be more cake.