As an undergraduate in the late '60s, I ran the microphones and lights for the Sunday chapel services.
The chapel's PA system was a high-class Altec-Lansing system, with a vacuum-tube mike mixer and power amplifier located at the front end of the sanctuary and a remote (opto-isolated) volume control knob in the balcony.
I would enter from the front end of the building, turn on the system at a master power switch, and walk to the stairs at the rear to ascend to my perch at the volume control and light switches.
One Sunday, when I was half-way to the back of the auditorium, there was a horrible feedback screech (after about 10 sec warm-up) and I ran back to the amplifier to kill power.
I went upstairs and found the knob turned full CW (maximum volume), which I reset to CCW, returned to turn the amplifier power on, and went back to the control and ran the system normally.
This happened once more. The third Sunday, I started upstairs at the volume control, found it at CW again, and started everything properly.
The elderly organist complained to me, and I replied "some idiot keeps turning the volume control to maximum while I'm gone".
She was taken aback, since the idiot was herself: Altec-Lansing had labelled the knob in dB attenuation, with CCW = 40 dB attenuation and CW = 0.
She had interpreted that as 0 being minimum volume (at CW).