And occasionally FA forget to pick up containers before taking off! I was on UA in F, going JFK-LHR, and had one of those on-ground plastic cup of orange juice. I didn't finish it, but the FA never came around to take it before take off. I had to hold it on while doing the takeoff roll and climb. And I was only 1 of 3 pax in FC, and the ONLY rev pax. So they couldn't have been too busy...

Of course the service wasn't very good on the rest of that flight.