Disable automatic code suggestions in RubyMine
Auto-suggestions in RubyMine have changed a lot since this card was written.
To disable the mostly useless automatic suggestion popups in RubyMine, go to File / Settings, then to Editor / General / Code Completion and uncheck Auto-display code completion.
You can still open the popup by pressing CTRL + Space. And you probably want to use Context-dependent word expansion instead, anyway.