Quote o' the day: apt-wat?
From the apt-get(8) man page:
remove is identical to install except that packages are removed instead of installed. Note the removing a package leaves its configuration files in system. If a plus sign is appended to the package name (with no intervening space), the identified package will be installed instead of removed.
In a burst of consistency, apt-get install can remove packages: "If a hyphen is appended to the package name (with no intervening space), the identified package will be removed if it is installed." It also gives some explanation: "These latter features may be used to override decisions made by apt-get's conflict resolution system."
Still, people think I'm weird.