You know how you know that you've really and truly left graduate school behind?
When you encounter dissertators from your alma mater, who are working in your exact subfield, and you've never heard of them.
Or when you saunter over to your grad program's webpage, and recognize only two or three students' names, vaguely--and they're all 6th or 7th years.
Or when a departing staff member posts dozens of pictures from his goodbye party to Facebook, and the only people you can identify are a couple of senior faculty. (Those others: are they grad students? Staff? Junior faculty? Who the hell knows?)
But that shudder that runs through you upon seeing photos of the department lounge, looking exactly as you remember it--down to the ectomorphic grad student checking his email while balancing a bag of books on his lap?
That's a sign that it hasn't been quite long enough.