What is the most important invention?

The most important invetion would have to be the building.

Without it, where would we live? Where would we sleep and stay when it was snowing, or when there was hail pelting us?

AnswerAsking a question like what is the most important anything is bound to create controversy. In my opinion, the most important invention was the hammer, as it jumpstarted the homo sapien species's creativity and caused them to realise they could create things to solve their problems.
Agriculture
the invention of the bong greatly reduced the damage inflicted upon a stoners lungs. the bong or "water pipe" used water to cool the smoke as it was pulled through.