(with thanks to Pathum Karunaratne for collecting them on his class 
Facebook page)

"Don't write anything that doesn't make sense."
"There is one way to be good, and so many ways to be bad."
"Differentiation is a skill, Integration is an art."
"It's best to stick to one standard of measurements. Then you won't lose your 
space shuttle ....in space."
"Let me erase this off the board before you are able to ask any questions."
"... always check by sketching. And so, when the vikings left scandinavia..."
"If you have a cat, you know a cat curls up at night. Suppose a spherical 
cat..."
"If at first you can't solve a problem, you should find a simpler problem that 
you can't solve!"
"I have in my notes to remind you that the Fundamental Theory of Calculus is a 
triumph of civilization"
"You should never go in the water 15 minutes after eating, and you should 
certainly never integrate across a singularity."
"Force is measured in newtons, after Isaac Newton.....not Fig Newtons.
"One of the appealing features of the midwest countryside is these water 
towers you get along the highway. I particularly like the one southwest of St. 
Louis. It says Bourbon on it."
"The one and only truth: Integral(2 Pi r)ds "
"If you take a cone and squash it... now don't try this with ice cream 
inside it..."
"A full period of sin^2(x) has 2 humps, which reminds me of an old joke.
Father camel had 2 humps. Mother camel had 1 hump. Their son had no humps, 
so they named him Humphrey."
"Now let's do some examples... especially since its so hot in here."
"The one and only way to be immortal is to prove a theorem."
"The common misconception is that mathematics is all about calculating things. 
Mathematics is more about how to avoid calculating things."
"Thats ok, we'll just add and subtract until our problems go away"
In reference to the proof of ln(xy)=lnx+lny:
"In fact, I'm going to put a box around this whole thing because I like it 
so much" 
"...now you have situations like the plague which wiped out a third of the 
population in a few years. I imagine that was a good time to buy a house..."
"Ah, America. The land of where if it rhymes it must be true."
On finding roots:
"If you get a quadratic, thats nice. Anything beyond that, there's no hope"
"I'm not publishing these notes, so I can tell you things that are not quite 
right."
"infinity minus infinty, now that's rubbish"