In a forest, a ferret bumps into a little mouse, and says, ``Hi, Junior, what are you up to?
``I'm writing a dissertation on how mice eat ferrets,'' said the mouse.
``Come now, friend mouse, you know that's impossible!''
``Well, follow me and I'll show you.'' They both go inside the mouse's dwelling and after a while the mouse emerges with a satisfied expression on his face.
Comes along a badger. ``Hello, what are you doing these days?''
``I'm writing the second chapter of my thesis, on how mice devour badgers.'
``Are you crazy? Where is your academic honesty?''
``Come with me and I'll show you.'' As before, the mouse comes out with a satisfied look on his face and a diploma in his paw.
Finally, the camera pans into the mouse's cave and, as everybody should have guessed by now, we see a mean-looking, huge Fox sitting next to some bloody and furry remnants of the ferret and badger.
The moral: It's not the contents of your thesis that are important --- it's your Ph.D. advisor that really counts.