Prince William knows it. I know it. Every football fan knows it. There is a moment when the game ceases to be a game. At some point, without your even realising it, football skews your priorities, heightens your emotions, deepens your mood swings, and helps you understand things about life that you might feel foolish explaining to non-believers.

Look, for instance, at the clips of William celebrating his beloved Aston Villa’s second goal in their Europa League victory last week. Essentially, never in the history of the British monarchy has a senior member of the Royal Family acted in such a way in public. The explosion of sheer, unbridled ecstasy in that defining moment, the clenched fist salute, the hugging and the jumping for joy – you can’t tell me that’s normal behaviour for a 43-year-old man, never mind the heir to the throne.

Such is the lot of every committed football fan. We are not bound by normal codes of behaviour. And so it was that I found myself, a man who found tears hard to come by at the death of his own mother, blubbing openly at the departure from my life of someone I have never met. But when Pep Guardiola said on Sunday that “deep inside, I know it’s my time. Nothing is eternal”, there cannot have been many among the 60,000 present at Manchester City’s Etihad Stadium for whom that didn’t stir emotions which had nothing to do with football.