Ask HN: What is your favorite tech talk?

What are your favorite talks that changed the way you think and you feel everyone needs to see? It could be related to software or any field that is enabled via technology. If you can add the link that would be cool as well.

the one where speaker draws parallels between today,s tech world and bronze age, and how even though bronze was a relatively simple technology, the know how was quickly lost when its supporting civilization collapsed... can,t find the link atm