Ten Things Beginners Should Know in Lightroom
10. The "F" key cycles through screen modes just like Photoshop. Your menus have gone missing? Press CMD+OPT+F (CTRL+ALT+F) to immediately return to the normal screen mode.
9. Side panels keep disappearing? Turn off Auto-Hide for Panels. Right-click the triangle icon on the side panels and change the setting to "Manual". Works for top & bottom panels as well. [More]