When you first open nano, it tells you at the bottom of the screen that you can press "Ctrl+G" for help. The second paragraph of the help text explains the '^' notation, and the help further explains that you could have accessed the help page by pressing F1, which has been a common key for accessing the help feature of whatever program you're using for decades.

These are people who prefer vim, and are perfectly fine with the :q magic.

Shift + zz