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Persistent undo and repeat
Like any editor, Vim keeps track of every operation. Press u to undo a last operation, and Ctrl + r to redo it.
To learn more about Vim's undo tree (Vim's undo history is not linear!) and how to navigate it, see chapter 4, Advanced Workflows .
Vim also allows you to persist undo history between sessions, which is great if you want to undo (or remember) something you've done a few days ago!
You can enable persistent undo by adding the following line to your .vimrc:
set undofile
However, this will litter your system with an undo file for each file you're editing. You can consolidate the undo files in a single directory, as seen in the following example:
" Set up persistent undo across all files.
set undofile
if !isdirectory("$HOME/.vim/undodir")
call mkdir("$HOME/.vim/undodir", "p")
endif
set undodir="$HOME/.vim/undodir"
If you're using Windows, replace the directories with %USERPROFILE%\_vim\undodir (and you'll be making changes to _vimrc instead of .vimrc).
Now, you'll be able to undo and redo your changes across sessions.