Okay, a friend of mine came up with this one.
Yoda is walking through the Jedi Temple on the way back from teaching a group of younglings, hobbling along, the tips of his ears drooping slightly. He mumbles to himself as he walks...
"Green. Hmph! Frog. Hmph! Ears like a gundark. HMPH!!! Not so small am I. Size matters not! Yes, size matters not! Keep saying that to myself I must! Control my anger I must...!" And so he goes, his ears twitching as he thinks of the scathing (and certainly untrue!) remarks of the smart-aleck children.
The next day, Yoda passes by Obi-Wan and Anakin in the hall, and his large little ears catch some of their conversation...
"Is THAT why you didn't choose a green crystal?"
"Well, I never could get it out of my mind that he was the color of bantha vomit. I'm sorry, Master, but I just couldn't take it!"
"Well, if you can fess up, I can. I thought he looked like something Dex scraped off the floor. Except that Dex would make it a more appetizing shade..."
Yoda stalks on, fuming, his little green ears turning pink at the tips. "Control--my--anger--I--must--must control...!"
The next day, Yoda is scheduled to dub a Padawan. So he stands on his little chair, trying to look big and important, the other Council members standing in a circle. The Padawan enters the darkened chamber, and all the Masters ignite their lightsabers. And Yoda's is the only green one. His hand starts shaking, and he clutches his saber in both hands. "CONTROL--MY ANGER--I--I--AHHHHH!!!!!!" He dubs the Padawan, all right--all the way through. Along with all the Masters. Finally he shuts off his lightsaber and sits down in his little chair.
"Control my anger I did."
Heigh ho, heigh ho, it's home to work I go!!