One day a wolf was walking along, and came upon a rabbit sitting in front of a computer, typing away. The wolf inquired of the rabbit as to what he was doing; the rabbit replied "Typing my dissertation."
"Your what?" said the wolf.
"My dissertation on 'How rabbits eat wolves'," replied the rabbit, somewhat annoyed by the interruption at this point.
The wolf, not surprisingly, expressed some doubt concerning this topic. The rabbit, begrudgingly, offered to demonstrate the main point of his dissertation, suggesting that the wolf follow him into his hole. The wolf (with a wolfish grin, no doubt) agreed, and down the hole they went. Several minutes later the rabbit re-emerged, and returned to typing his dissertation. This series of events was repeated several more times that day, each time a wolf going down the hole with the rabbit, but only the rabbit coming back out again.
Finally, a man walked by, and struck by the unusual sight of a rabbit typing, stopped to ask what he was working on. The rabbit, truly exasperated now, again stated he was trying to finish his dissertation, entitled "How rabbits eat wolves." The man replied, almost as astonished as the wolves earlier in the day, "I assume this is not just a piece of theoretical work?" "Oh no, this is an experimental study. Would you like to see?"
And so down the hole they went. Once inside the rabbit's hole, the man discovered, to his horror, a large pile of wolf bones, and a rather larger lion calmly chewing on the remains of another wolf....
The moral, of course, is that it is not your dissertation topic that matters; rather, it is who your advisor is.