Will it click?

The newly married John tried to repair an ancient vacuum cleaner but all the bits flew round the room. He never ever mastered DIY skills.

Sixty years later the simple task of changing a light bulb defeated him. He screwed in the new bulb but no light appeared. No matter how hard he screwed success eluded him.

After Andy Mann had established there was a flow of electricity he placed his hand on the bulb and the magic light appeared.

“Ah,” said John. “Did I not tighten it enough?”

“No. It was too tight. I just loosened it a notch.”