I’ve just spent some significant amount of time working on notebook and restarted computer without saving or committing notebook.
As soon as I have realized what happened I was devastated. Couple of hours of work were gone for good. 🙁
Luckily , it is possible to retrieve history of the commands from the notebook itself. Just run next command and it will dump all it has to a text file :
%history -g -f my_notebook_code.txt