Okay so this would be like saying:

Every Californian lives on Main Street. Sarah lives on Main Street. Therefore Sarah lives in California.

Disregard my reply bc in the skills builder, they add that you have to add a slash through the second symbol (the necessary)

The way I'm understanding it is because when you negate all, it leaves it open to interpretation. For example, if we say "All New Yorkers ride the train" and we want to negate it, it would be an assumption to say none do. Because if all don't, some still might. Please correct me if I'm wrong

This has been the best explanation so far. Thanks!