Odd behavior
MacBook Pro is asking for password on bootup despite Require Password being unchecked in the General Tab in Security Settings
MacBook Pro with Retina display, OS X Yosemite (10.10.1)
That option only lets you wake up your Mac without typing a password. Instead, go to System Preferences -> Security & Privacy -> General, press the padlock and uncheck "Disable automatic login". Another way to do this is to go to System Preferences -> Users & Groups -> Login Options, and choose your user next to "Automatic login".
If you have FileVault turned on, remember that you have to type the password every time you turn on your Mac, and in this case, it cannot be disabled.