You've really never used CTRL+X F to look up a file name in vim?
I tried 'Ctrl-x' but it decrements the integer under the cursor by 1. I tried 'f' but it starts a new motion command to search the next occurrence of the character following it to the right. Example: 'fx' will place the cursor on the next occurrence of 'x' to the right.
How can I use 'Ctrl-x f' to look up a file name?
Here is a description of it and a few other insert mode commands: https://georgebrock.github.io/talks/vim-completion/
I've bound some complete-plug-in to tab, but that's pretty much all I do in insert-mode command-wise.