A young and eager apprentice mathematician approached a topologist sage.
"Master, wherefore do you pour coffee on this donut?"
"The beginner's mind is clouded by the sea of details to which he is a slave. This is not a donut."
"But if it does not have the donut-nature, what is it?"
"There is no donut-nature either, budding grasshopper. I pour coffee onto this two-dimensional compact manifold because I am a machine that turns coffee into theorems."
"And wherefore do you not use a coffee cup instead?"
"I am she who sees no difference between a coffee cup and a donut."
The apprentice received from the sage a delicious cream-filled coffee cup and was enlightened.