Prof: "A microcontroller is a complete computer in one single chip that costs only 1$."
Student: "I can't believe that. It might take years for me to really understand how that is meant."
Future Prof with a CP/AVR µc: "Take this µc and plug it in your USB-Serial Adapter. Open your terminal program and you'll see the prompt of a operating system that allows you all basic operations, such as: Creating a folder, writing a text document and executing programs. The µc contains enough eeprom for you to save many text documents and other stuff. And all text messages you see in your terminal program come from the CP/AVR µc."
Student: "Then a µc must be indeed a tiny but full working computer, because I can edit text documents and type commands. It only needs a big computer for a user interface. It's so fascinating and so cheap and available everywhere. I want to learn everything about microcontrollers."