Have you ever added a new command or option to your .vimrc and not see the changes reflected?

The reason might be that the option is being overriden by another plugin. The verbose command in Vim shows you what the current value is as well as where it is being defined.

:verbose set conceallevel

This outputs:

conceallevel=0
Last set from ~/.vim/plugged/vim-devicons/plugin/webdevicons.vim line 326

Vim makes it easy to open a URL in your browser while navigating a file.

Put the cursor over a URL in normal mode. Then type gx.