Question: Electric fans are often controlled by a knob which the user turns to power the fan on or off, and control the fan's speed.

On a lot of fans, the knob goes immediately from the off position to the highest speed, followed by the other speed settings in descending order. 

For example on the picture below, you can see the knob going from the off position ('0') to the highest ('3'), and then the other two in descending speed order ('2', '1').

![box fan top](https://i.stack.imgur.com/B4xgB.jpg)

Why is that?

Answer: 
I think it is to protect the ensure the motor starts, because if low is first, low end motors might not be able to start.
My guess is that...

Imagine you have to operate the device in darkness (no light environment) or someone with visual difficulties, placing the off setting next to the highest allow the user to know they've switched off the device.

See it this way, you are at position 2, your intention is to switch off the fan, you knob in the "0,1,2,3" setting, you will not be able to tell immediately if you are at the 1 position or off position as the fan is turning at a similar pace. (Slower but unable to identify easily). 

Whereas, by placing the setting as "1,2,3,0", you will be able to tell immediately if you are at position 3 (faster and louder noise) or at position 0 (significantly slower and lesser noise). Thus, user in dark places can "feel" the setting without looking at the knobs. 

Don't shoot me if I'm wrong, this is just my guess. Cheers. =)