Quote of the Day: Conservation of Pain

Me, to my (graduate-level) ODE students in office hours this afternoon:

"The amount of pain is conserved.

[nontrivial pause, while I think about the accuracy of my statement]

(Well, technically, the amount of pain is non-decreasing.)"

Update: This quote was quite a doozy. It's the type of quote that, when my professors accidentally backed into them, I liked to write them down for posterity.