We are in the media room of the Dublin Tech Summit, and Martin Sorrell is quizzing me. We’d been discussing the impact he believes artificial intelligence will have on advertising ahead of a fireside chat. Sorrell has, over decades, been at the forefront of the global advertising industry so he can see better than most what this disruptive force might mean, but now our conversation has turned to the late Tony O’Reilly.  He wants to know everything, as the two men were friends and he would have liked to have attended his funeral last week. “He was one of the…