I got stuck in a Vim window yesterday while doing a Git merge after pulling updates. Git wanted me to provide a reason for the merge, which it had never asked for before while doing a merge. I didn't want to enter a reason; at that point I just wanted to cancel the merge to figure out what had gone wrong. But I had to close the whole window as I couldn't figure out how to quit Vim.
So today I happened to do a search on it, and was amused by these pages: