Check this out.

This is the UI for Adobe Reader that you use to Navigate through the pages in a PDF. Clicking the buttons move through the pages one at a time in each direction.

Guess what keyboard keys you have to use to navigate through the pages of the same PDF … the Left and Right Keys!

Very bad dissonance there, because the arrows keep making you think you should be hitting the up and down buttons to move through the pages.
Those icons should be left and right arrows to match the keyboard navigation and send a good visual cue to the user about what keys to hit. #dontmakemethink