I used to work in a quality control lab. We did tests and also tagged the pallets as they came through.
I was in the lab one day. A forklift driver pulled up outside the lab with a load. I saw him through our big window. He held up his index finger...and I looked up. I didn't see anything up there, so I looked back at him.
He smiled and did it again. And I looked up again. Nothing was up there.
He shook his head, and did the finger-crook 'come here' gesture. I walked to the window, pressed my face up against the glass, and looked up to see what he was pointing at above him.
Nothing up there, either.
The driver got off the forklift and walked into the lab. He laughed, held up his index finger again and said, "ONE. I have ONE pallet that needs to be tagged."