Don't forget: In AC8, the escape key now performs the cancel function. This makes it consistent with all other software in the solar system. 99% of the time, hitting ESC will be faster than mousing over to the Cancel button, or right-click-canceling.
It's also another beautiful, inspiring, timeless, indestructible tower on the magisterial edifice that is The Keyboard, as compared to the moldy-straw-1st-little-pig-shack of Mousing Around Clicking Buttons, Menus, Sub-menus, and Sub-sub-menus.
In other words, learn the shortcuts, and use them. And we'll plan our escape.