Pro-Catalonia protesters stay on Barcelona streets

The video discusses the concept of 'Dover north' and clarifies that there was never a '13'.

What does the speaker emphasize about the number 13?

• It was often overlooked.

• It was sometimes present.

• It never existed.

• It was always present.

What is introduced by the speaker after discussing the number 13?

• A historical event.

• A mathematical formula.

• A new theory.

• The concept of 'Dover North'.