What's The Most Important Invention?

[JoeMoma]

Toilet Paper!

 

[Circe]

There's an existing similar thread, but the choices were sort of tongue-in-cheek, and I'd rather get a sense of what people think has been really important and take a somewhat more serious approach to it.

Of course, something like the wheel was a game changer. But was it as big a game changer when invented as, say, the cellular phone was when it was invented? Basically, which had the greatest positive impact on society when it was invented?

So, what do you believe is the most important invention of all time, and why? There are no right or wrong answers here.

Toilets. Major, major lifesaver from disease.

 

[Quasar44]

The radio
Allows humans to master radio waves and communicate at very long distances