How do I restore the behavior of the fn key after Mojave update? I updated to Mojave yesterday and my fn key seems to have changed behavior.  Previously, I could hold fn and press delete to foward delete.  Now, if I press the fn key, it has different behaviors.

In spotlight, it clears my search.  In chromes URL window, it highlights the URL.  In vim, I'm not really sure what it's doing but it exits insert mode as a result.  I miss my fn key. :(
Soooo . . . I've done this to myself.  I'm not sure how I've done it, and I don't like answering my own questions, but in case anybody else finds themselves in this situation . . . here goes.

I never use caps lock so I typically remap caps lock to control.  While I was doing this, evidently, I also remapped fn to escape by accident.


Apple > System Preference > Keyboard
Click 'Modifier Keys'
Sometimes there's a dropdown allowing you to remap the fn key (it seems like it's only there when you have an external keyboard too which may be why I couldn't find it when I looked here before to reset the behavior)