I painstakingly wrote a question up, not realizing I wasn't logged in. When I was done, I noticed that there was a log-in button below the question box, so I assumed that's what I needed to do to proceed with posting my question.

After I logged in, I was taken back to the home screen, not my post. When I used my browser's back button to go back to my question, everything I had typed was gone. This is extremely frustrating. If you log in from the Ask Question page using the inline log-in button, it should save the state of the question.