It is the little known fact that graduate students are among the most miserable peoples in the world.
Yes, the first year begins in high spirits, but then gradually, inch by inch, the lonely misanthropic gloom settles in, brought on by the low pay, the low status, the low self-esteem, and above all the low muffled beating of the unfinished dissertation, which, like the tell-tale heart, lies insistently beneath the floorboards of the mind.
I remember the low, muffled beating. Or was it beatings? Ah, what's the difference.
On a related note, I always felt, while in grad school, that most of the other people I knew could have used this etiquette lesson.