There’s one, specific hotkey command that saves my bacon about 25 times a day: Control-Shift-T, which reopens the last tab closed. When you’ve got 70 or so different tabs open, you’re bound to close the wrong one from time to time.
That’s why it behooves you to memorize this command. Better yet, take a few moments to learn some of the other hotkeys shown here that will help you zip through your tabs, close them all, or quit Chrome altogether. Just as hotkeys help you work faster in Windows, the same level of convenience applies to Chrome.