A friend of mine had just served out the breakfasts coming in from Hong Kong one morning. She got to the back, stowed everything away and turned to face the cabin. Then they hit a huge airpocket.
She said that it all happened in slow motion..... most of the trays were hovering in midair, along with other items, and then the aircraft levelled out and, well, picture the entire cabin covered in porridge and juice!
Years ago I stood in the back galley of a 737, we hit thermal turbulence and 2 unsecured canisters came out of their stowages. One missed me, one hit me. I had just gotten over that, trying to take my seat and strap in when we hit another airpocket and suddenly I lurch up into the air and bang my head on the ceiling. Thankfully, neither incident hurt!!