>>15 - On installing linux software.
Regular users are unwilling to use the command line, and most graphical package managers don't provide enough information about what software does, how ready it is for general use and which features it provides. It's a nightmare compared to what it could be like.
Windows is pretty bad in this regard too. Wizards where you have to click "next" for 2 minutes and have to make choices about which components to install also suck.