Tech things everyone should know

OK, so the other day I'm talking with someone at work about a problem w/ some systems. Basically we have a couple of PCs with very large Dell monitors, which for some reason aren't hooked up. I talked more multiple people and the response I kept getting was that the computers didn't have enough power for the monitors, to which my response was always "huh?"
After finally taking a look at the systems themselves, I realized that they only had VGA ports, and the monitors only had DVI inputs. You would not believe how long it took to explain to people about what a video card is, and how we just needed another type of video card to connect to the monitors. The simple concept of a video card seemed to be too much for most of the people I talked to.
In my extensive time working in tech, I've discovered that there's a lot of things that people don't seem to know, and that I have to keep reminding myself is not common knowledge. So, here's a quick list of things that you ought to know if you work with computers in any capacity (not "If you fix computers for a living" - just "if you work with a computer in the course of your regular job, particularly if you work for a tech company").

1) What is an IP address. I'm shocked at how often I'm trying to explain something to somebody and the whole concept is so foreign. An IP address is a unique number that identifies your computer on a network, like a phone number identifies your phone. Is that so hard to memorize or understand?
Extra credit 1: The concept of private vs. public IP addresses, even more credit for knowing the private subnets (at least the popular two).
Extra credit 2: How to determine your IP address on your computer

2) The concept of network storage. Again, if I had a nickel for every time someone told me they put something on their "M drive" with no idea whatsoever of what that means...well, I'd have a lot of nickels. I could understand it back in the mid-90's, but c'mon! The concept has not changed at all since it was introduced a loooong time ago.

3) Viruses and spyware are bad, even if they're not messing up your life too badly. Again, in the "if I had a nickel" department, folks who's computers are just completely infested with crap, so badly that I'm scared to plug my laptop into their network. When I ask them "how long have these porn pop-ups been appearing?" the answer is usually in terms of weeks or months. The fact that you didn't seek help until your system was unusable indicates an underestimation on your part of the seriousness of the infections. Funny how people don't do this with anything else: "Well, the car has been getting slower and slower, now it won't go more than 25mph, but since I can get anywhere I need to by city streets, I'm not really concerned about what might be wrong. Maybe I'll contact a mechanic when it starts topping out at 10mph". And most of this experience is from when I was the I.T. guy at work (i.e. it didn't even cost them anything).

4) You don't have to double-click everything. Yeah, maybe it's obvious to you, but you would be amazed at how often I see people still double-clicking everything, be it a folder, a link in a web browser, or whatever. Lots of times this can really screw things up (for example double-clicking the Submit button in a web form will make it run twice).

5) Know what to look for in a new computer. This one comes up a lot - someone calls me up, since I supposedly know a lot about "computers" and tells me they're thinking about buying a new one - there's an ad in the paper for a computer for $499, and it has a 100GB hard drive - that's a good deal, right? Of course, there are a lot of nuances regarding pricing, but the main things you should be concerned with are CPU type/speed and RAM. Of course, the rankings of "adequate / better / more than you need" are constantly changing, but everyone's got someone they can call and ask about that. And, the most important thing to know is that HARD DRIVES ARE CHEAP! A computer with a 200GB HD is not worth twice as much as one with a 100GB HD. Seems obvious to you? Believe me, it's not to most people. Oh yeah, and one other thing people don't seem to get: in terms of bang for your buck, laptops are a hell of a lot more expensive to buy, prone to break, and expensive to fix, so don't get one unless you really need the mobility.

6) Applications cannot be transfered by copying files. This one doesn't necessarily qualify, since you need to have some basic understanding of files etc. to make this mistake, but a lot of people mistakenly believe that when they buy a new computer, they should be able to just copy their applications from the old computer onto the new one. Unfortunately this almost never works - I don't expect people to understand the registry (least of all because then they'll probably also discover the regedit command and that's game over), but people really ought to know that you can't just copy an application from one machine to another. I do have a lot of forgiveness for this one, though, since the assumption seems pretty logical on the surface, and I don't expect the layman to know about the registry.

I have, of course, left out a lot of other stuff that seems basic to me but I understand is foreign to people who don't work with this stuff on a regular basis. I mean, I get that most people don't want to know any more about their computer than they need to in order to get the job done, but seriously - these are just really basic things that everyone ought to know.