A "Smart people only" sign should go right over the "No crime allowed" sign.
That being said, I can feel you neighbor. I used to sell $5000 computers in the mid 90s. I will never work retail again, too many people expecting to get shafted, and when you're THE tech guy, all the folks trying to beat you on the sales floor do everything in their power to turn you into the Repair guy, and earning minimum wage.
When you troubleshoot someone's new pistol, there is only so much they could have done to it that you can't have seen.
Other than the floods of porn viruses, illegal pictures, and people walking into the shop expecting you to turn water into wine, we'd tech ANYONE"S broken down machines in the name of good service. Usually for absolutely free.
"My cupholder broke off" (CD-Rom tray)
"I broke the foot pedal, and do you have larger rubber stops I can glue to it to make it easier to doubleclick? " (mouse)
"How do you stop the mouse from leaving rubber marks on the screen? "
"I bought this monitor and keyboard at Goodwill, how do I connect them to get onto the internet to type my term paper" " Ok, what kind of computer do you have" "Oh I don't have one... The guy at goodwill said I did not need one. " (hit speakerphone at this point) " You need something between the keyboard and the monitor... " "Don't Lie to me, you just want to screw me out of my money, Give me your Manager, it's obvious you don't want to keep your job" "(manager next to me chimes up, along with 2 very regular customers) "Miss, I'm the Manager and I've listened to the entire call... if the gentleman at Goodwill is willing to teach you how to attach a monitor and keyboard together, and you trust him, then go ask him how it works, If you want to argue with us, and not listen to what we have to tell you, when YOU called us... there isn't much we can do to help you, Have a nice day.(click) !
At least they weren't trying to build *ahem* Companion Robots... those guys used to spend a lot on actuators.... but you wanted a shower after dealing with them.
Side note... When removing my loaded pistol from my belt at my LGS for Service or during a "passing around" (when other customers gone) I ask before I even touch it, remove the mag and then unsnap, and present the entire holster, Butt first and let him finish making the weapon safe the way that makes him most comfortable.
He made a joke about it once... I asked if they'd prefer if I pointed the gun at the wall, and snapped the slide back to send the round airborne and catch it instead?