If you experience an Mac OS X program to freeze and you cannot exit it by clicking quit or using a keyboard shortcut, you can always force it to quit using the Activity Monitor.
If you put your computer into hibernation, the next time you turn it on, you'll get all your windows and programs open just the way they were before the shutdown.
Some installations or settings changes require you to restart your computer. In most cases you don't need to actually reboot it, you only need to restart the explorer.exe process.
Sometimes we don't want others to know about our newest relationship gains or losses. This is the way your friends and other Facebook users won't even notice it when you change it.
Remember as a kid you played with a mirror, putting your face to the side of it and your friends were laughing at the funny symmetry of your face and your faces reflection?
