I wish I had the file on my computer at home... a few years ago, some of my students started writing down quotes from me in calculus and physics classes. Upon graduation a year ago, one of the students presented me a file with quotes from the classes... at least I know that by saying quotable things, I was keeping their attention on what I was saying.
A few I remember
"There are four methods to solving a problem like this. Unfortunately, two of those methods are the same as the other two methods."
Upon learning about Newton's law of cooling and approaching the problem using differential equations with an integrating factor; we had just completed a CSI type of problem about a murder victim's body temperature and estimating the time of death.
"So, what did we learn from this problem?" <a few gratuitous student responses, not really close to what I was really looking for, so I went in a totally different direction...> "That's really not the important thing. I think that what we learned is that if you're ever going to kill someone, bring bags of ice. That way, you can create a perfect alibi. Jeez, I keep trying to keep this course so you can apply it to the real world, but you guys keep missing the important points."
The valedictorian swore that she was going to use that quote during her speech at graduation: "if you're ever going to kill someone, bring bags of ice."