I think the person you are replying to was using notebook as shorthand for interactively. You don't write scripts that you call, you have to have a repl open to interactively feed code to.

Autocompletion in Julia is also just terrible and the tooling really is lacking compared to better funded languages. No harm in admitting that (when Julia had no working debugger some people were seriously arguing that you don't need one: Just think harder about your code! Let's please bury that attitude...)