In normal text editors [with all due respect to Vim] there is a shortcut Ctrl+Z when you have done something nasty and want to return to the previous version of the text. Like BACK button in Word. I wonder how can you achieve this behaviour in Vim.
Here is a trick though. You can map the Ctrl+Z keys.
This can be achieved by editing the .vimrc file. Add the following lines in the '.vimrc` file.
nnoremap <c-z> :u<CR> " Avoid using this**
inoremap <c-z> <c-o>:u<CR>
This may not the a preferred way, but can be used.
** Ctrl+Z is used in Linux to suspend the ongoing program/process.
I had the same problem right now and i solved it. You must not need it anymore so I write for others:
if you use gvim on windows, you just add this in your _vimrc:
$VIMRUNTIME/mswin.vim behave mswin
else just use imap...
Just in normal mode press:
On a mac you can also use command Z and that will go undo. I'm not sure why, but sometimes it stops, and if your like me and vimtutor is on the bottom of that long list of things you need to learn, than u can just close the window and reopen it and should work fine.
The answer, u, (and many others) is in $ vimtutor.
Source: Stackoverflow.com