I worked at a university help desk in the late 1980's. At the time, the university was gradually allowing access to their computer systems via dialup, at the blazing speeds of 1200 and 2400 bps. The help desk had obtained a licensing agreement with Kermit software, where we were granted permission to distribute their software for students, faculty and staff to access the systems. So, we'd come up with detailed step-by-step instructions, including screenprints, which made the process of installing and running the software completely idiot-proof. All anyone had to do was come by and pick up a floppy, and they'd be able to log on with their existing user ids. About all they had to know that wasn't in the instructions was what speed their modem was.
About a month after we started doing this, I received a call. "This is Dr. Smith, in the Physics department. I came by yesterday, and picked up a copy of Kermit. But I can't seem to make it work. Can you help?"
"Sure thing." I spent a few minutes walking him through the setup process. We got to the point where he needed to know what speed his modem was. "Sir, what speed is your modem?" I asked.
Silence. Then, "What's a modem?"