[jerojero]

Agriculture is the most important set of techniques and technologies in human history, it gave us the possibility of staying in a place.

There's also fire.

Writing was very important, I'm not so sure about industrialization, maybe as modern men we might think that way. But human life was perfectly liveable and conceivable without it. Even writing. Big civilizations like the Inca empire didn't really have writing (although they had the quipu system for record keeping).

If there's a civilization collapse, we will still be doing fire and agriculture. We probably won't be doing industrialization and computers.

[Certhas]

Fire predates modern humans. I will concede agriculture as up there with the two I mentioned, but I think you underestimate how radical the shift of industrialisation was/is, and I think this is because history teaches us about highly atypical lives from the past. City dwellers, kings, etc...

In fact you could reasonably argue that life for most people didn't change that much from establishing agricultural settlements all the way up to industrialization. Most people spent most of their time procuring food and clothing/shelter using roughly similar methods.