Sheryl, the exact same thing happened to me! I was going to post it but kept being distracted. Thanks for doing it!
I created a text box and I didn't like the way the text was right up against the margin so I hit the tab key and everything went away! I pressed the tab key again, and it all came back.
This, and the backslash key (or is it a forward slash?) the one to the right of the bracket keys are very handy because that one toggles the view of between everything in the workspace and the document only.