Hugo

There is a real reason, and the pull cord is the clue that ties it together: it is about keeping mains voltage away from wet hands.

European wiring rules divide a bathroom into zones measured from the bath or shower, and each zone limits what may be installed in it. Ordinary switches and sockets are restricted in the zones nearest the water. A small bathroom can easily be almost entirely inside a restricted zone, at which point there is nowhere compliant to put a switch.

That leaves two compliant options, and you have seen both:

• Put the switch outside the door.
• Use a pull cord, where the only thing your wet hand touches is an insulating string and the switch mechanism itself sits in the ceiling, well away from everything.

Countries where the switch is inside the bathroom generally have rules written around a different assumption — usually that a residual current device on the circuit handles the risk, so the switch position matters less.

You have moved from hard water to soft water, and the surprise is that soft water is the one behaving correctly.

Hard water contains dissolved calcium and magnesium. Those react with soap to form an insoluble scum — the grey ring in a bathtub, the film on a shower screen. That reaction consumes soap, which is why hard-water areas need more of it to lather, and it also strips the remaining soap off your skin quickly, which is what you have learned to interpret as "rinsed".

Soft water has almost none of those minerals, so nothing destroys the soap. It stays dissolved, keeps working, and continues to make your skin slippery until it is physically washed away by volume.

So the slippery feeling is not leftover soap sitting on you so much as soap doing its job in the absence of anything to stop it. People moving in the other direction, from soft to hard, complain that soap will not lather and their skin feels tight and squeaky — the same difference read from the other end.