When Callie is talking to Finn trying to explain Meredith's behavior, she says, "It's the doctor thing. Four years of high school, four years of college, four years of med school - by the time we graduate we are in our late 20's and we've never done anything but go to school and think about science." Finn would have spent the same amount of time in school in order to become a veterinarian.
First time someone calls Meredith 'dark and twisty'
The outfit Izzie is wearing in the flashback to the intern mixer is the same one she wore on her big date with Alex.
On September 21st, 2006, CTV, the Canadian network that airs Grey's Anatomy (2005), accidentally broadcast the wrong episode - instead of airing the season premiere, they broadcast the second episode of the new season instead. The mistake made national news in Canada and generated some angry fan backlash, but was rectified a week later when the correct episodes were aired.