What was it about a tragic story of a big boat and forbidden love that hit a nerve and became the biggest grossing movie of all time (which it did on this day)? Was it the water? The uniforms? The frenetic Irish dancing? Or a combination of any two of them? We may never know, but it was the film that made the most money until Avatar stole its damp and salty crown. But as the same bloke made both, he’s probably not too bovved.