I had an instructor for Hardware Installation and Maintainence who was rather...absent minded. He knew the stuff for the most part, but communicating it was an entirely different matter. And then he did occasionally forget things. One of the teams lost their motherboard after he said the extra power cord off the power supply should go in the digital audio header on the back of the CD-ROM. I asked if he was sure about that, he said we could try leaving it out. Most of the class listened but that one team was stuck without a MB for about a week :)

Then there's Andy... He just plain gets his words wrong, mixes up buzzwords and such. Not such a big deal if it weren't for the fact that the people he's teaching don't know the stuff (to be expected)...

Community colleges are fun :)