Long story short. The euro is a attempt at unifying currencies and standardize trade agreements and trade walls. Before the UK leaves that agreement it needs to ensure trade options still remain open and those that dont, they have renegotiation terms with. Why is the world watching??? the success of this exit would signal the end of the euro, as more and more countries will use it as a template to leave. At the end of the day the only real effect it will have on NZ is the way in which the govt negotiates future deals.
in the late 70s the world moved from cash to currencies. currencies have a different form than cash. EU was the next step in unification. It has now become a failed experiment