chmod 0644 is indeed bad advice in ~/.netrc. Similarly, [Esc] :wq is not too helpful at a bash prompt. If you don't know the difference you're not yet ready for the magic post-it note.
My point is that if you don't understand what chmod 0644 does, you probably shouldn't use it as general advice. chmod 0640 would be better general advice, but it's not a fix-all.
Ditto `:wq`. If you're in vim, and you don't know how to exit, you probably don't want the random keypresses you made while trying to figure out how to exit to be written to the file. Another case where an alternate version might be better: [ESC]:q! nano <file>
