Diversions

The shower I use in the on-campus gym has a handheld head in addition to the standard one, so it has a flow diverter valve.

Unlike other flow diverter valves I have used, if you inadvertently turn the valve too far in one direction, the handle will come loose and be forced out by water pressure, you will get hit in the chest with a stream of water, and you will let out a yelp or other exclamatory noise.

After a split second trying to push the handle in against the water pressure, I turned off the water and screwed it back in.