I was modeling a ceramic mug, and I had the “cylinder” part all done. Then I started on the handle. Somehow, when I went back from edit mode for the handle, not only could I not find the mug, but all my layers buttons were missing in the 3D view. The mug (“cylinder”) still showed up in my outliner, and I could select it, and even see it’s material. I tried selecting it and snapping it to the cursor, but nothing showed up. Maybe somehow I moved it to another layer, BUT, I couldn’t switch to any other layers because the layer buttons had disappeared. I’m sure I pressed some key combination, but I can’t find out what I did.
Never mind…more research solved it. Seems I was in “Local” view and not “Global”. Everything is a learning experience.