1. That I don't have to pay money to get my hands on a credible operating system.
2. There are far more Linux distros available that I have time to try them out.
3. Switching to Linux does not mean trouble-free computing.
4. Whenever you ask a Linux user which is the best distro, invariably the answer you'll get is the name of the distro that they're using.
5. In my opinion, the best Linux distro is Ubuntu.
6. No matter how much I like a GUI, and no matter how lazy years of using Windows made me, there's a lot to be said for using a command line.
If a subordinate asks you a pertinent question, look at him as if he had lost his senses. When he looks down, paraphrase the question back at him.