There aren't many occasions when you can use the excuse "but it's my first day!"
Today was my first day working as an actual doctor and getting paid to do doctoring. Although I'm contracted at a large regional hospital, my first rotation is in a smaller town at a GP clinic. In fact, the same GP clinic where I spent all of 2010. So I'm not new. The doctors all know me, the nurses know me, the reception and admin staff know me. I know how to use the computers and how to set up the right printer. Still, one of the practice partners spent several hours going through all that with me this morning.
After that I had an hour for lunch, and then when I came back they gave me a laptop and sent me home for the day.
Try as I might, I just couldn't throw in the "it's my first day!" excuse.