This troper does tech support for DSL modems, and there are five words that make him cringe every time: "I ran the CD and..." This CD is inside a sealed cardboard envelope that's marked, "'''DO NOT RUN UNLESS INSTRUCTED BY A TECHNICIAN'''" because it will create errors in the modem (it's only used for a specific situation that doesn't apply to most customers). It's actually relieving to hear this, come to think about it, because then the customer's problem is easy to identify and fix, but still.

Common problem with IT: If you give someone a new device and some sort of storage medium, he or she will almost invariably run the medium, apparently because the ditz thinks that he/she ''needs'' to run the medium for the device to work properly. At the company where a friend worked, the IT guys used to take all the [=CDs=] from the packaging of company laptops before handing them out for this exact reason.

At the lab where this troper works, some memory modules were damaged after a lightning strike. They were tagged "DEFECTIVE! DO NOT USE UNLESS YOU LIKE SYSTEM CRASHES!". A few hours later, someone saw those modules and thought it would be a good idea to install them on their workstations. Cue an endless supply of Windows crashes and Linux kernel panics. Or, worse, on the computer that controls $5000 worth of test equipment (it is an aging, slow Pentium 4 box which has not seen a Windows reinstall in 4 years, becoming an EldritchAbomination on its own - but it does well, as long as you DO NOT USE IT for anything other than controlling the equipment).

During a fantasy roleplaying game this troper played in, the GM managed a particularly good use of this trope. The party found itself in a room with two doors, one of which was guarded by an invincible, uncorruptible swordsman. The party spent almost an entire session trying to figure how to defeat, bribe, and/or trick the swordsman in order to get through the door. When we finally managed it, we found that behind the door we had spent all this time obsessing over was a small closet filled with cleaning supplies. Behind the OTHER door was a room filled with blue mist capable of turning the players into gods...

This troper has a friend who will not look twice at a girl... until someone tells him "You should stay away from her, she's crazy/her boyfriend will beat the crap out of you/she's a vampire". Then he's utterly fascinated.

This troper is tasked with bar training all new employees at the coffee shop where she works. The very first thing she does is point to a button on the espresso machine and say, "Okay, I know it says 'push'. Really don't push it." The next thing she has to do is grab the new hire's wrist as their hand heads unerringly for the button. "See, the ''reason'' you shouldn't push it is that is causes all the pressure in the machine to drop to one atmosphere and we won't be able to use it for an hour. So don't push it."

"Don't fall for best friend's girlfriend, don't fall for best friend's girl-oh bollocks..."