It was hailed as a triumph but then so was Gallipoli. In truth, it was a disaster so savage that it has reduced the Prime Minister to mooching about in off-season Ibiza. There he sulks, rousing himself only to kick a piece of rented furniture and put another Pingu DVD on for the kids, now horribly aware that as a player on the global stage he ranks a couple of rungs beneath those Dublin crooners, Jedward.

To deal first with what Little Gove persists in calling "the positives": there is no doubt that Mrs C and Mrs Obama could special relationship for England. They proved to be thoroughly at ease in each other's company, whether listening to one of the Queen's anecdotes or eating salad.

The problems were all on the spear side. Again looking for one of Gove's positives, it can be said with confidence that the US president managed
to remember the PM's name for the entirety of the trip, but frankly you would expect as much from a former professor of constitutional law at the University of Chicago. But, that aside, nothing. I have not spent time with two people who have so little in common since, in my youth, I mistakenly went to a nightclub with Edwina Currie and Sir Nicholas Fairbairn.

There were efforts at conversation, Dave stolidly keeping up a commentary on the weather and Barack dropping the odd aphorism for his retinue of biographers. But the president's heart was not in it. He had crossed the Atlantic for a 40-million-vote photo opportunity with a pint of Guinness and, after travelling so far, realised that it would be damaging, perhaps fatally, to the "essential relationship" (one of mine) if he couldn't be fagged to go the extra mile.

Having made the effort to show up, he sleepwalked through the rest of the trip. Even his speech in Westminster Hall (predominantly one of mine - the president thought he could wing it with a PowerPoint presentation and I had to be summoned hastily to a working breakfast) was, let's be honest, a mix and mash and rehash of that tired "we are all one civilisation" trope.

As for the game of table tennis (organised, I kid you not, as some kind of put-down to Boris - "You can have the Olympics, I'm playing with Obama"), well, you had to be there. It was nearly as viscerally embarrassing as the moment when Clegg sidled up to Obama unbidden, brandishing a ten-pack of Silk Cut Ultra, and asked, "Fancy a crafty one round the back?" with such vehemence that the president was forced to call in security.

Dave remained Tiggerish in the presence of the man he wishes would be his mentor right until the utter end, when even he had to accept brute reality.

This realisation dawned when, after the PM had chased the presidential entourage to say goodbye and thank them for coming and imploring, "We must do this again . . . soon?" the president replied, simply: "Why?"