When I was 6 or 7 we had these electric yo-yos that lit up when spinning. One of them wouldn’t work, and my friends mom was trying to test the lightbulb with t

When I was 6 or 7 we had these electric yo-yos that lit up when spinning. One of them wouldn’t work, and my friends mom was trying to test the lightbulb with two AA batteries stacked on top each other and the light bulb on positive saying the light was burnt out. I remember being frustrated trying to explain to her that the light could never work this way. Of course she knew better, and explained that a wire to the negative lead wasn’t needed because she was using 2 batteries. She was so confident.